With the old fbx converter 3.5 of filmbox (Motionbuilder) or the old .flm format before it was renamed .fbx did work. But now its not backwards compatible with new versions 5 and 6. Thats why the old importer that seems to be in Carrara and i guess other apps hence the reason why we cant import from one app to another with regards to skins materials and animation. But there maybe a small solution from this company if i am reading it correctly. Here is the link:

http://www.okino.com/conv/imp_fbx.htm The okino fbx importer

they seem to have been able to import skins and animation etc.....