diff --git a/CHANGES b/CHANGES
index 94afc578..ee2be870 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+2012-12-10: Fix spurious error when running netperf-wrapper with a test name
+            that is also an existing file name (that is, make the error message
+            intelligible).
+
 2012-12-09: Automatically switch CDF plots to log scale if the median values
             differ by more than an order of magnitude.
 
diff --git a/netperf_wrapper/formatters.py b/netperf_wrapper/formatters.py
index dc8a61ae..a30ce843 100644
--- a/netperf_wrapper/formatters.py
+++ b/netperf_wrapper/formatters.py
@@ -339,7 +339,9 @@ def _do_cdf_plot(self, results, config=None, axis=None, postfix=""):
             # More than an order of magnitude difference; switch to log scale
             axis.set_xscale('log')
             min_val = min(self.min_vals)
-            axis.set_xlim(left=min_val-min_val%10) # nearest value divisible by 10
+            if min_val > 10:
+                min_val -= min_val%10 # nearest value divisible by 10
+            axis.set_xlim(left=min_val)
 
     def _do_meta_plot(self, results, postfix=""):
         for i,config in enumerate(self.configs):
diff --git a/netperf_wrapper/settings.py b/netperf_wrapper/settings.py
index 24e9036b..88e67064 100644
--- a/netperf_wrapper/settings.py
+++ b/netperf_wrapper/settings.py
@@ -175,7 +175,10 @@ def load_test(self, test_name):
             self.HOST = self.HOSTS[0]
 
         test_env = TestEnvironment(self.__dict__)
-        s = test_env.execute(os.path.join(TEST_PATH, test_name + ".conf"))
+        filename = os.path.join(TEST_PATH, test_name + ".conf")
+        if not os.path.exists(filename):
+            raise RuntimeError("No config file found for test '%s'" % test_name)
+        s = test_env.execute(filename)
 
         for k,v in list(s.items()):
             if k == k.upper():
@@ -230,9 +233,6 @@ def load():
 
         test_name = args[0]
 
-        if os.path.exists(test_name):
-            test_name = os.path.splitext(os.path.basename(test_file))[0]
-
         settings.load_test(test_name)
         results = [ResultSet(NAME=settings.NAME,
                             HOST=settings.HOST,