Agg backend problem with 0.53

It's evidently something to do with threads and is probably

    > an inherent problem with Agg. I'm just bringing this to the
    > attention of others here who may be having similar
    > problems. Perhaps John knows what's going on and whether
    > anything can be done about it. The convenience of working in
    > SciTE For the moment,

I would be very surprised if it's agg - I think it's a GUI conflict on
the Tk side. Todd is this related to the idle -n thingie? If so,
perhaps a FAQ and status report are warranted.

Gary, since you say GTK is working, you may also want to check GTKAgg
which will help up narrow it down to Tk, and would rule out agg
problems. But since SciTE is GTK based, you probably need make sure
that matplotlib is not firing up it's own gtk mainloop, by not calling
'show'. You can show your GTK figures manually if necessary by doing

   manager = get_current_fig_manager()

This is a GTK specific call applicable only if the GTK mainloop is
already running (as I suspect it is in SciTE, which I haven't used),
It is probably a good idea to standardize the API here across GUIs to
handle exactly this case.

The larger question is why would there be a GTK/Tk conflict? In any
case, let us know if you learn anything else.