diff --git a/tools/plotting/scatterplot_code.py b/tools/plotting/scatterplot_code.py
index ce0b42f775c..a8797292612 100644
--- a/tools/plotting/scatterplot_code.py
+++ b/tools/plotting/scatterplot_code.py
@@ -18,10 +18,13 @@ def get_columns( input ):
                 for col in range(1, input.metadata.columns+1):
                     try:
                         val = float(elems[col-1])
+                        valid = True
                     except:
                         val = elems[col-1]
                         if val:
-                            if val.strip().lower() != "na":
+                            if val.strip().lower() == "na":
+                                valid = True
+                            else:
                                 valid = False
                         else:
                             valid = False
diff --git a/tools/stats/cor_code.py b/tools/stats/cor_code.py
index ce0b42f775c..a8797292612 100644
--- a/tools/stats/cor_code.py
+++ b/tools/stats/cor_code.py
@@ -18,10 +18,13 @@ def get_columns( input ):
                 for col in range(1, input.metadata.columns+1):
                     try:
                         val = float(elems[col-1])
+                        valid = True
                     except:
                         val = elems[col-1]
                         if val:
-                            if val.strip().lower() != "na":
+                            if val.strip().lower() == "na":
+                                valid = True
+                            else:
                                 valid = False
                         else:
                             valid = False
diff --git a/tools/stats/gsummary.py b/tools/stats/gsummary.py
index 143d3fcb317..86b9955f033 100755
--- a/tools/stats/gsummary.py
+++ b/tools/stats/gsummary.py
@@ -143,7 +143,7 @@ def read_table(datafile, cols):
         try:
             exec code
         except Exception, e: 
-            stop_err(e)
+            stop_err(str(e))
         return (skipped_lines, first_invalid_line, d)
     else:
         return (skipped_lines, first_invalid_line, None)