Hey Ideasman, I just wanted to get back to you on this.
I found that the exporter works fine from inside Blender on Windows with python 2.51. Since it also works fine from the command line I figured it had to be a problem with the GUI, so I set to debugging.
Near as I can tell, the problem lies in how you’ve done the buttons. The problem comes from this block of code:
if GLOBALS['EVENT'] == EVENT_FILESEL:
txt = 'Batch FBX Dir'
name = Blender.sys.expandpath('//')
txt = 'Export FBX'
name = Blender.sys.makename(ext='.fbx')
Blender.Window.FileSelector(fbx_ui_write, txt, name)
Or rather, doesn’t come from it – the GLOBALS[‘EVENT’] == EVENT_FILESEL condition is never reached on my Mac, no matter how much you push the button. Again, on my PC it works fine.
It seems you’re using some undocumented button functions and not using the Register() functionality… Any particular reason you’ve done it this way?