Oops, i fixed that already a month ago, but for some unknown reason i haven't pushed the commit. I did it now. It's in git master, source/glexemel/g3d_support.py or just use this link:
http://glestae.git.sourceforge.net/git/gitweb.cgi?p=glestae/glestae;a=blob_plain;f=source/glexemel/g3d_support.py;hb=HEAD
(Right-click 'Save As', name it g3d_support.py, in blender: File->User Preferences -> Addons -> Install Addon (bottom), pick the downloaded file, enable it)
I'm very lazy at fixing the importer as nobody seems to use it anyway.
Btw, before you ask: Animation isn't imported. You only get some shape keys.
I think they are currently make some kind of contest to get rid of as many importers/exporters as possible or something like this grrrrrrr
Welcome to the world of API changes. That's not the first time nor will it be the last.