I updated my Ubuntu 12.04 box yesterday (normal daily updates proposed by ubuntu at startup, not an upgrade). Specifically there was an update of thunderbird (and firefox). I didn't check what pakages were updated.

Now, thunderbird seems to work but all the icons (accounts, folders, sent folders) are the same (standard folder icon in nautilus for instance). Also the folders containing unread messages are no longer in bold.

Is anyone being affected by this? Any workaround?