Same problem with me (I'm using testing): I think it's the gnome 2.4/2.6 mix. There is also some 2.4 stuff left in unstable I've seen. Hope for you they will soon be updated
My desktop is totally messed up, the gnome-applets were upgraded: most of my applets don't work now: I've switched to Enlightenment temporarily (I already had it installed) cause gnome is just one big mess.
I hope this will be over soon...
I don't want to sound like an alternative healer, but: it will probably get worse before it's over