Just notied there's a standalone converted for FBX to 3DS/DWG/OBJ http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=10775855
Maybe there's some luck with this...
Two suggestions that sometimes work for Mac users:
Delete, move or rename the SU Preferences file so that it creates a new, clean one.
Repair your disk permissions.
Anssi