I've once again reviewed the _scproxy code and that code seems correct (although that doesn't say too much for subtle bugs because I wrote the initial version of the module).

Dan: is it possible to tell moviegrabber to use another python installation (in particular /Library/Frameworks/Python.framework)? If so, is the problem reproducable with the latest binaries on www.python.org?

The crash report says that the actual crash occurs inside a function called by SCDynamicStoreCopyProxies and I wouldn't know how Python's use of that function is wrong. 

The crash could still be caused by the way the moviegrabber application uses python, but I'd consider that a bug in moviegrabber unless there is a clear indication of a bug in python itself.

BTW. Is Moviegrabber this software? : http://sourceforge.net/projects/moviegrabber/