I'm running a recent build from source (last week) on OSX 10.6.6 and the Python 2.6.1 that ships with the OS. When I use the macosx backend, any plot that I generate results in a window that hangs. The Python dock icon bounces for awhile, then when it stops, the spinning beach ball appears and I am unable to interact with the window. I can, however, add plots to the window and update its contents with show(). This behaviour does not occur with other backends (e.g. TkAgg). I have tried switching interactive mode off in matplotlibrc, but this does not fix the problem.
Thanks in advance for any ideas.