diff --git a/examples/undocumented/libshogun/converter_sobi_bss.cpp b/examples/undocumented/libshogun/converter_sobi_bss.cpp
index 14f663d3f4a..fc021817dc7 100644
--- a/examples/undocumented/libshogun/converter_sobi_bss.cpp
+++ b/examples/undocumented/libshogun/converter_sobi_bss.cpp
@@ -91,7 +91,9 @@ void test()
 	std::cout << "Separation error: " << sep_error << std::endl;
 
 	SG_UNREF(sobi);
+	SG_UNREF(mixed_signals);
 	SG_UNREF(signals);
+	
 	return;
 }
 
diff --git a/src/shogun/mathematics/ajd/ApproxJointDiagonalizer.h b/src/shogun/mathematics/ajd/ApproxJointDiagonalizer.h
index 689ccad61aa..3d84d71c3a9 100644
--- a/src/shogun/mathematics/ajd/ApproxJointDiagonalizer.h
+++ b/src/shogun/mathematics/ajd/ApproxJointDiagonalizer.h
@@ -54,8 +54,8 @@ class CApproxJointDiagonalizer : public CSGObject
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> &C,
-						   SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> C,
+						   SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 						   double eps=CMath::MACHINE_EPSILON,
 						   int itermax=200) = 0;
 
diff --git a/src/shogun/mathematics/ajd/FFDiag.cpp b/src/shogun/mathematics/ajd/FFDiag.cpp
index 4b0a74fc221..365ede1d0a4 100644
--- a/src/shogun/mathematics/ajd/FFDiag.cpp
+++ b/src/shogun/mathematics/ajd/FFDiag.cpp
@@ -16,7 +16,7 @@ using namespace shogun;
 
 void getW(double *C, int *ptN, int *ptK, double *W);
 
-SGMatrix<float64_t> CFFDiag::diagonalize(SGNDArray<float64_t> &C0, SGMatrix<float64_t> V0,
+SGMatrix<float64_t> CFFDiag::diagonalize(SGNDArray<float64_t> C0, SGMatrix<float64_t> V0,
 						double eps, int itermax)
 {
 	int n = C0.dims[0];
diff --git a/src/shogun/mathematics/ajd/FFDiag.h b/src/shogun/mathematics/ajd/FFDiag.h
index 9a172e4352c..a9678c22ac5 100644
--- a/src/shogun/mathematics/ajd/FFDiag.h
+++ b/src/shogun/mathematics/ajd/FFDiag.h
@@ -53,8 +53,8 @@ class CFFDiag : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> &C,
-       							SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> C,
+       							SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 							double eps=CMath::MACHINE_EPSILON,
 							int itermax=200);
 
@@ -65,8 +65,8 @@ class CFFDiag : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> &C,
-						   SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> C,
+						   SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 						   double eps=CMath::MACHINE_EPSILON,
 						   int itermax=200)
 		{
diff --git a/src/shogun/mathematics/ajd/JADiag.cpp b/src/shogun/mathematics/ajd/JADiag.cpp
index a6641ebdc84..256cb975ddd 100644
--- a/src/shogun/mathematics/ajd/JADiag.cpp
+++ b/src/shogun/mathematics/ajd/JADiag.cpp
@@ -17,7 +17,7 @@ using namespace shogun;
 void jadiagw(double c[], double w[], int *ptn, int *ptm, double a[],
 	         double *logdet, double *decr, double *result);
 
-SGMatrix<float64_t> CJADiag::diagonalize(SGNDArray<float64_t> &C, SGMatrix<float64_t> V0,
+SGMatrix<float64_t> CJADiag::diagonalize(SGNDArray<float64_t> C, SGMatrix<float64_t> V0,
 						double eps, int itermax)
 {
 	int d = C.dims[0];
diff --git a/src/shogun/mathematics/ajd/JADiag.h b/src/shogun/mathematics/ajd/JADiag.h
index 5783ca9c02d..db36337cfda 100644
--- a/src/shogun/mathematics/ajd/JADiag.h
+++ b/src/shogun/mathematics/ajd/JADiag.h
@@ -53,8 +53,8 @@ class CJADiag : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> &C,
-       							SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> C,
+       							SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 							double eps=CMath::MACHINE_EPSILON,
 							int itermax=200);
 
@@ -65,8 +65,8 @@ class CJADiag : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> &C,
-						   SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> C,
+						   SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 						   double eps=CMath::MACHINE_EPSILON,
 						   int itermax=200)
 		{
diff --git a/src/shogun/mathematics/ajd/JADiagOrth.cpp b/src/shogun/mathematics/ajd/JADiagOrth.cpp
index aed3c8ca8a8..fc60180d82c 100644
--- a/src/shogun/mathematics/ajd/JADiagOrth.cpp
+++ b/src/shogun/mathematics/ajd/JADiagOrth.cpp
@@ -19,11 +19,11 @@ void left_rot_stack(double *A, int M, int N, int K, int p, int q, double c, doub
 void right_rot_stack(double *A, int M, int N, int K, int p, int q, double c, double s);
 void left_rot_simple(double *A, int m, int n, int p, int q, double c, double s);
 
-SGMatrix<float64_t> CJADiagOrth::diagonalize(SGNDArray<float64_t> &C, SGMatrix<float64_t> V0,
+SGMatrix<float64_t> CJADiagOrth::diagonalize(SGNDArray<float64_t> C, SGMatrix<float64_t> V0,
 						double eps, int itermax)
-{
+{	
 	int m = C.dims[0];
-	int L = C.dims[2];	
+	int L = C.dims[2];
 
 	SGMatrix<float64_t> V;
 	if (V0.num_rows != 0)
@@ -40,28 +40,28 @@ SGMatrix<float64_t> CJADiagOrth::diagonalize(SGNDArray<float64_t> &C, SGMatrix<f
 
 	while (more)
 	{
-        more = false;
-
-        for (int p = 0; p < m; p++)
-        {
-            for (int q = p+1; q < m; q++)
-            {
-                // computation of Givens angle
-                double theta = givens_stack(C.array, m, L, p, q);
-
-                // Givens update
-                if (fabs(theta) > eps)
-                {  
-                    double c = cos(theta);
-                    double s = sin(theta);
-                    left_rot_stack (C.array, m, m, L, p, q, c, s);  
-	                right_rot_stack(C.array, m, m, L, p, q, c, s);  
-	                left_rot_simple(V.matrix, m, m, p, q, c, s);
-                    rots++;
-                    more = true;
-                }
-            }
-        } 
+		more = false;
+
+		for (int p = 0; p < m; p++)
+		{
+			for (int q = p+1; q < m; q++)
+			{
+				// computation of Givens angle
+				double theta = givens_stack(C.array, m, L, p, q);
+
+				// Givens update
+				if (fabs(theta) > eps)
+				{  
+					double c = cos(theta);
+					double s = sin(theta);
+					left_rot_stack (C.array, m, m, L, p, q, c, s);  
+					right_rot_stack(C.array, m, m, L, p, q, c, s);  
+					left_rot_simple(V.matrix, m, m, p, q, c, s);
+					rots++;
+					more = true;
+				}
+			}
+		} 
 	}
 	
     return V;
@@ -70,33 +70,33 @@ SGMatrix<float64_t> CJADiagOrth::diagonalize(SGNDArray<float64_t> &C, SGMatrix<f
 /* Givens angle for the pair (p,q) of a stack of K M*M matrices */
 double givens_stack(double *A, int M, int K, int p, int q)
 {
-    int k;
-    double diff_on, sum_off, ton, toff;
-    double *cm; // A cumulant matrix
-    double G11 = 0.0;
-    double G12 = 0.0;
-    double G22 = 0.0;
-
-    int M2 = M*M;
-    int pp = p+p*M;
-    int pq = p+q*M;
-    int qp = q+p*M;
-    int qq = q+q*M;
-
-    for (k=0, cm=A; k<K; k++, cm+=M2) 
-    {
-        diff_on = cm[pp] - cm[qq];
-        sum_off = cm[pq] + cm[qp];
-
-        G11 += diff_on * diff_on;
-        G22 += sum_off * sum_off;
-        G12 += diff_on * sum_off;
-    }
+	int k;
+	double diff_on, sum_off, ton, toff;
+	double *cm; // A cumulant matrix
+	double G11 = 0.0;
+	double G12 = 0.0;
+	double G22 = 0.0;
+
+	int M2 = M*M;
+	int pp = p+p*M;
+	int pq = p+q*M;
+	int qp = q+p*M;
+	int qq = q+q*M;
+
+	for (k=0, cm=A; k<K; k++, cm+=M2) 
+	{
+		diff_on = cm[pp] - cm[qq];
+		sum_off = cm[pq] + cm[qp];
+
+		G11 += diff_on * diff_on;
+		G22 += sum_off * sum_off;
+		G12 += diff_on * sum_off;
+	}
     
-    ton  = G11 - G22;
-    toff = 2.0 * G12;
+	ton  = G11 - G22;
+	toff = 2.0 * G12;
 
-    return -0.5 * atan2 ( toff , ton+sqrt(ton*ton+toff*toff) );
+	return -0.5 * atan2 ( toff , ton+sqrt(ton*ton+toff*toff) );
 }
 
 /* 
@@ -105,42 +105,42 @@ double givens_stack(double *A, int M, int K, int p, int q)
 */
 void left_rot_stack(double *A, int M, int N, int K, int p, int q, double c, double s )
 {
-    int k, ix, iy, cpt;
-    int MN = M*N;
-    int kMN;
-    double nx, ny;
-
-    for (k=0, kMN=0; k<K; k++, kMN+=MN)
-    {
-        for (cpt=0, ix=p+kMN, iy=q+kMN; cpt<N; cpt++, ix+=M, iy+=M) 
-        {
-            nx = A[ix];
-            ny = A[iy];
-            A[ix] = c*nx - s*ny;
-            A[iy] = s*nx + c*ny;
-        }
-    }
+	int k, ix, iy, cpt;
+	int MN = M*N;
+	int kMN;
+	double nx, ny;
+
+	for (k=0, kMN=0; k<K; k++, kMN+=MN)
+	{
+		for (cpt=0, ix=p+kMN, iy=q+kMN; cpt<N; cpt++, ix+=M, iy+=M) 
+		{
+			nx = A[ix];
+			ny = A[iy];
+			A[ix] = c*nx - s*ny;
+			A[iy] = s*nx + c*ny;
+		}
+	}
 }
 
 /* Ak(mxn) --> Ak(mxn) x R where R rotates the (p,q) columns R =[ c s ; -s c ] 
    and Ak is the k-th M*N matrix in the stack */
 void right_rot_stack(double *A, int M, int N, int K, int p, int q, double c, double s ) 
 { 
-    int k, ix, iy, cpt, kMN; 
-    int pM = p*M;
-    int qM = q*M;
-    double nx, ny; 
-
-    for (k=0, kMN=0; k<K; k++, kMN+=M*N)
-    {
-        for (cpt=0, ix=pM+kMN, iy=qM+kMN; cpt<M; cpt++) 
-        { 
-            nx = A[ix]; 
-            ny = A[iy]; 
-            A[ix++] = c*nx - s*ny; 
-            A[iy++] = s*nx + c*ny; 
-        } 
-    }
+	int k, ix, iy, cpt, kMN; 
+	int pM = p*M;
+	int qM = q*M;
+	double nx, ny; 
+
+	for (k=0, kMN=0; k<K; k++, kMN+=M*N)
+	{
+		for (cpt=0, ix=pM+kMN, iy=qM+kMN; cpt<M; cpt++) 
+		{ 
+			nx = A[ix]; 
+			ny = A[iy]; 
+			A[ix++] = c*nx - s*ny; 
+			A[iy++] = s*nx + c*ny; 
+		} 
+	}
 }
 
 /* 
@@ -148,17 +148,17 @@ void right_rot_stack(double *A, int M, int N, int K, int p, int q, double c, dou
 */
 void left_rot_simple(double *A, int m, int n, int p, int q, double c, double s)
 {
-    int ix = p;
-    int iy = q;
-    double nx, ny;
-    int j;
-
-    for (j=0; j<n; j++, ix+=m, iy+=m) 
-    {
-        nx = A[ix];
-        ny = A[iy];
-        A[ix] = c*nx - s*ny;
-        A[iy] = s*nx + c*ny;
-    }
+	int ix = p;
+	int iy = q;
+	double nx, ny;
+	int j;
+
+	for (j=0; j<n; j++, ix+=m, iy+=m) 
+	{
+		nx = A[ix];
+		ny = A[iy];
+		A[ix] = c*nx - s*ny;
+		A[iy] = s*nx + c*ny;
+	}
 }
 #endif //HAVE_EIGEN3
diff --git a/src/shogun/mathematics/ajd/JADiagOrth.h b/src/shogun/mathematics/ajd/JADiagOrth.h
index 590d4f2a8fa..e1a8ce78a3d 100644
--- a/src/shogun/mathematics/ajd/JADiagOrth.h
+++ b/src/shogun/mathematics/ajd/JADiagOrth.h
@@ -53,8 +53,8 @@ class CJADiagOrth : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> &C,
-       							SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> C,
+							SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 							double eps=CMath::MACHINE_EPSILON,
 							int itermax=200);
 
@@ -65,8 +65,8 @@ class CJADiagOrth : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> &C,
-						   SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> C,
+						   SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 						   double eps=CMath::MACHINE_EPSILON,
 						   int itermax=200)
 		{
diff --git a/src/shogun/mathematics/ajd/UWedge.cpp b/src/shogun/mathematics/ajd/UWedge.cpp
index e3702382166..629894fc846 100644
--- a/src/shogun/mathematics/ajd/UWedge.cpp
+++ b/src/shogun/mathematics/ajd/UWedge.cpp
@@ -14,7 +14,7 @@ typedef Matrix< float64_t, Dynamic, Dynamic, ColMajor > EMatrix;
 
 using namespace shogun;
 
-SGMatrix<float64_t> CUWedge::diagonalize(SGNDArray<float64_t> &C, SGMatrix<float64_t> V0,
+SGMatrix<float64_t> CUWedge::diagonalize(SGNDArray<float64_t> C, SGMatrix<float64_t> V0,
 					double eps, int itermax)
 {
 	int d = C.dims[0];
diff --git a/src/shogun/mathematics/ajd/UWedge.h b/src/shogun/mathematics/ajd/UWedge.h
index a46edc44a04..c0443be8472 100644
--- a/src/shogun/mathematics/ajd/UWedge.h
+++ b/src/shogun/mathematics/ajd/UWedge.h
@@ -52,8 +52,8 @@ class CUWedge : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> &C,
-       							SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		static SGMatrix<float64_t> diagonalize(SGNDArray<float64_t> C,
+       							SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 							double eps=1e-12,
 							int itermax=200);
 
@@ -64,8 +64,8 @@ class CUWedge : public CApproxJointDiagonalizer
 		 * @param itermax maximum number of iterations
 		 * @return V the matrix that best diagonalizes C 
 		 */
-		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> &C,
-						   SGMatrix<float64_t> V0= SGMatrix<float64_t>(NULL,0,0),
+		virtual SGMatrix<float64_t> compute(SGNDArray<float64_t> C,
+						   SGMatrix<float64_t> V0 = SGMatrix<float64_t>(NULL,0,0),
 						   double eps=1e-12,
 						   int itermax=200)
 		{
diff --git a/tests/unit/converter/ica/Jade_unittest.cc b/tests/unit/converter/ica/Jade_unittest.cc
index 76269a8e1b6..05009ce46df 100644
--- a/tests/unit/converter/ica/Jade_unittest.cc
+++ b/tests/unit/converter/ica/Jade_unittest.cc
@@ -61,6 +61,7 @@ TEST(CJade, blind_source_separation)
 	EXPECT_EQ(isperm,true);
 
 	SG_UNREF(jade);
+	SG_UNREF(mixed_signals);
 	SG_UNREF(signals);
 }
 
diff --git a/tests/unit/converter/ica/SOBI_unittest.cc b/tests/unit/converter/ica/SOBI_unittest.cc
index 09c75f3b301..8e0939d3879 100644
--- a/tests/unit/converter/ica/SOBI_unittest.cc
+++ b/tests/unit/converter/ica/SOBI_unittest.cc
@@ -56,6 +56,7 @@ TEST(CSOBI, blind_source_separation)
 	EXPECT_LE(sep_error, 1e-6);
 
 	SG_UNREF(sobi);
+	SG_UNREF(mixed_signals);
 	SG_UNREF(signals);
 }