diff --git a/python/plugins/fTools/tools/doRandPoints.py b/python/plugins/fTools/tools/doRandPoints.py
@@ -225,7 +225,7 @@ def randomize(self, inLayer, outPath, minimum, design, value):
         add = ( 100.00 - 70.00 ) / len(points)
         for i in points:
             outFeat.setGeometry(i)
-            outFeat.addAttribute(0, QVariant(idVar))
+            outFeat.setAttribute(0, QVariant(idVar))
             writer.addFeature(outFeat)
             idVar = idVar + 1
             count = count + add

diff --git a/python/plugins/fTools/tools/doRegPoints.py b/python/plugins/fTools/tools/doRegPoints.py
@@ -147,7 +147,7 @@ def regularize(self, bound, outPath, offset, value, gridType, inset, crs):
                     pGeom = QgsGeometry().fromPoint(QgsPoint(x, y))
                 if pGeom.intersects(bound):
                     outFeat.setGeometry(pGeom)
-                    outFeat.addAttribute(0, QVariant(idVar))
+                    outFeat.setAttribute(0, QVariant(idVar))
                     writer.addFeature(outFeat)
                     idVar = idVar + 1
                     x = x + pointSpacing

diff --git a/python/plugins/fTools/tools/doSumLines.py b/python/plugins/fTools/tools/doSumLines.py
@@ -143,7 +143,7 @@ def compute(self, inPoly, inLns, inField, outPath, progressBar):
                         length = length + distArea.measure(outGeom)
             outFeat.setGeometry(inGeom)
             outFeat.setAttributes(atMap)
-            outFeat.addAttribute(index, QVariant(length))
+            outFeat.setAttribute(index, QVariant(length))
             writer.addFeature(outFeat)
             start = start + 1
             progressBar.setValue(start)

diff --git a/python/plugins/fTools/tools/doVectorGrid.py b/python/plugins/fTools/tools/doVectorGrid.py
@@ -193,8 +193,8 @@ def compute( self, bound, xOffset, yOffset, polygon ):
                 pt2 = QgsPoint(bound.xMaximum(), y)
                 line = [pt1, pt2]
                 outFeat.setGeometry(outGeom.fromPolyline(line))
-                outFeat.addAttribute(0, QVariant(idVar))
-                outFeat.addAttribute(1, QVariant(y))
+                outFeat.setAttribute(0, QVariant(idVar))
+                outFeat.setAttribute(1, QVariant(y))
                 writer.addFeature(outFeat)
                 y = y - yOffset
                 idVar = idVar + 1
@@ -213,8 +213,8 @@ def compute( self, bound, xOffset, yOffset, polygon ):
                 pt2 = QgsPoint(x, bound.yMinimum())
                 line = [pt1, pt2]
                 outFeat.setGeometry(outGeom.fromPolyline(line))
-                outFeat.addAttribute(0, QVariant(idVar))
-                outFeat.addAttribute(1, QVariant(x))
+                outFeat.setAttribute(0, QVariant(idVar))
+                outFeat.setAttribute(1, QVariant(x))
                 writer.addFeature(outFeat)
                 x = x + xOffset
                 idVar = idVar + 1
@@ -238,11 +238,11 @@ def compute( self, bound, xOffset, yOffset, polygon ):
                     pt5 = QgsPoint(x, y)
                     polygon = [[pt1, pt2, pt3, pt4, pt5]]
                     outFeat.setGeometry(outGeom.fromPolygon(polygon))
-                    outFeat.addAttribute(0, QVariant(idVar))
-                    outFeat.addAttribute(1, QVariant(x))
-                    outFeat.addAttribute(2, QVariant(x + xOffset))
-                    outFeat.addAttribute(3, QVariant(y - yOffset))
-                    outFeat.addAttribute(4, QVariant(y))
+                    outFeat.setAttribute(0, QVariant(idVar))
+                    outFeat.setAttribute(1, QVariant(x))
+                    outFeat.setAttribute(2, QVariant(x + xOffset))
+                    outFeat.setAttribute(3, QVariant(y - yOffset))
+                    outFeat.setAttribute(4, QVariant(y))
                     writer.addFeature(outFeat)
                     idVar = idVar + 1
                     x = x + xOffset

diff --git a/src/core/qgsfeature.cpp b/src/core/qgsfeature.cpp
@@ -18,6 +18,11 @@ email                : sherman at mrcc.com
 #include "qgsgeometry.h"
 #include "qgsrectangle.h"
 
+#ifdef QGISDEBUG
+#include "qgsmessagelog.h"
+#include <QObject>
+#endif
+
 /** \class QgsFeature
  * \brief Encapsulates a spatial feature with attributes
  */
@@ -167,6 +172,20 @@ void QgsFeature::initAttributes( int fieldCount )
 }
 
 
+bool QgsFeature::setAttribute( int idx, const QVariant &value )
+{
+#ifdef QGISDEBUG
+  if ( idx < 0 || idx >= mAttributes.size() )
+  {
+    QgsMessageLog::logMessage( QObject::tr( "Attribute index %1 out of bounds [0;%2[" ).arg( idx ).arg( mAttributes.size() ), QString::null, QgsMessageLog::WARNING );
+    return false;
+  }
+#endif
+
+  mAttributes[idx] = value;
+  return true;
+}
+
 bool QgsFeature::setAttribute( const QString& name, QVariant value )
 {
   int fieldIdx = fieldNameIndex( name );

diff --git a/src/core/qgsfeature.h b/src/core/qgsfeature.h
@@ -140,7 +140,7 @@ class CORE_EXPORT QgsFeature
     const QgsAttributes& attributes() const { return mAttributes; }
     QgsAttributes& attributes() { return mAttributes; }
     void setAttributes( const QgsAttributes& attrs ) { mAttributes = attrs; }
-    void setAttribute( int field, const QVariant& attr ) { mAttributes[field] = attr; }
+    bool setAttribute( int field, const QVariant& attr );
     void initAttributes( int fieldCount );
 
     /**Deletes an attribute and its value*/