The problem does still exist (Python 2.6b2).

I attached a patch for Tkinter.py which addresses this problem. It is
the same as in the first proposed fix, but adds an additional check
whether the menu item has a 'command' property.
I also removed the "INDEX2 (is included)" comment, as it is not the
desired behavior (see http://www.tcl.tk/man/tcl8.5/TkCmd/text.htm#M98).
I cannot confirm the behavior, but it should be a separate issue
nevertheless.