Possible fix for 2.6 versions of Matplotlib

Long standing issue with multiple plots being added to a single canvas.

Calling canvas.draw() appears to be the "correct" way to do this in pythin 2.6

Need someone to test if this still works in python 2.5

pyfpdb/GuiGraphViewer.py

@@ -126,10 +126,11 @@ class GuiGraphViewer (threading.Thread):
     #end def get_vbox
 
     def clearGraphData(self):
-        self.fig.clf()
+        self.fig.clear()
         if self.canvas is not None:
             self.canvas.destroy()
 
+        if self.canvas == None:
             self.canvas = FigureCanvas(self.fig)  # a gtk.DrawingArea
 
     def generateGraph(self, widget, data):
@@ -197,6 +198,7 @@ class GuiGraphViewer (threading.Thread):
 
             self.graphBox.add(self.canvas)
             self.canvas.show()
+            self.canvas.draw()
             #self.exportButton.set_sensitive(True)
     #end of def showClicked