Lost group after upgrade and GDM issue

[Sylvain Archenault <sylvain.archenault@laposte.net>]

Hello,

I'm running sid, and after a recent upgrade (I could not pin point 
exactly which one), my user lost all of the groups it was part of. I 
added them back manually, but I'm still unable to mount USB drive from 
nautilus automatically:

# groups sylvain
sylvain : sylvain adm disk lp cdrom sudo audio video plugdev fuse 
scanner bluetooth saned

Any idea which group i'm missing?

Also, from gnome, when I click on logout, X/Gdm3 crashes. I'm not sure 
what is the pb. I couldn't find a log to give me an idea of the problem, 
any idea where I should look at?

Thanks
Sylvain