Fix for the spin viewer window for wxPython 2.9.3.1.
This 2.9 fix is for when you right click in the tree view panel on nothing, and is compatible with wxPython 2.8. This fix will be required for the Mac application which will use this version.
Authored by: bugman 2012-04-13
Parent: [r15702]
Child: [r15704]
