Ah, thanks, there it is... I thought this must be dealt with somewhere but couldn't find it.  Maybe should add something to the 'exec' statement docs http://docs.python.org/py3k/library/functions.html#exec to reference this (from a usability-of-docs standpoint).

BTW, my code already sends the namespaces to exec (from current stack frame; it's part of a debugger) and probably would break other cases to alter this.

Well, anyway, sorry for the invalid bug report...