So I’ve been experiencing issues with Pidgin randomly freezing, locking up, and behaving erratically in Ubuntu 9.04 Jaunty. I looked into the issue and ran into this bug. If you’re unfamiliar, Canonical did some significant changes to libnotify in 9.04 and that bug seemed to tip me off to the problem.

I use the nVidia restricted drivers as well so it could be a problem in that arena, but if you’re suffering from the issue, until it gets fixed, you can just disable the Pidgin libnotify plugin (go to your Plugins menu and uncheck the “Libnotify Popups” plugin). This should fix the issue, I’ll correct myself if it doesn’t.