Hi there,
I'm a newbie poster that thought you should about an issue I encountered the other day, using the latest FBX importer/exporter in Maya 2012 (hotfix 2 x64).
Basically when I export a skinned character model from Maya to FBX and then import it back into Maya I can't use maya's paint skin weights tool on it. It comes up with an error saying it can't find the .liw attribute in the character's bones. This error occurs because the skinClusterInflMenu.mel script uses the short name for the attribute, while it appears the process of exporting to FBX removes the shortname of the lockInfluenceWeights attribute, leaving only an attribute called .lockInfluenceWeights and not .liw.
I just adjusted the skinClusterInflMenu.mel script to use the long name too and the paint skin weight tool works again.
I just thought you should know.
or am I missing setting an option in the FBX exporter/importer?