Comment 5 for bug 495361

Jerome - Thank you. Did you also upgrade to Xubuntu 9.10? This is normally a direct result of the upgrade. Unfortunately, the easiest fix I know does remove your configuration setup.

Before you log in, try the following:
1. Ctrl+Alt+F2 (go to a tty)
2. log in with your user name and password
3. go to ~/ (this is your /home directory)
    be careful to type the right things here, we are removing hidden directories, so they do start with dots
4. type rm ~/.cache and hit enter
5. type rm ~/.config and hit enter
6. Alt+F7 to go back to GDM
7. make sure you select XFCE-SESSION
8. log in

You should now only have one xfce-session to pick from on that gdm screen and you should get a desktop every time.