first... sorry for my english... I have this problem:
Just after installing Skype and/or qbittorrent, when I run it, my Unity 3D session crashes (with an ugly screen effect) and get back to gdm in order to login again. I don't know why it happens in my clean installation of ubuntu 11.10. In natty both worked fine.
Probably you need more info about my PC. From natty to oneiric I only got problems changing nouveau drivers for propietary nvidia drivers (finally I got it works fine -I suppose it-).
Update: I have confirm in my PC that maybe it is a problem with QT: VLC also crashes my desktop.
I would like Skype and qbittorrent work again (and VLC). Thank you very much for your help.
Installing all libqt4-* does'nt solve the problem :(