Xubuntu. Login problems after upgrading from 11.04 to 11.10

Last week I upgraded my Xubuntu from 11.04 to 11.10, and, as I’d feared, it didn’t work on the first try.
The symptoms were as follows: gdm started successfully, but I couldn’t log in with my own user account—it would kick me back to the login screen (gdm). New accounts, however, could log in successfully.
I compared my configuration files with those of another account and found nothing suspicious, except that there were files in my home directory that weren’t owned by my user.

Solution

Switch to one of the terminals (for example, tty1) using Ctrl+Alt+F1 and enter the following:

sudo chown -R <username>:<usergroup> /home/<username>
sudo shutdown -r now

This solved my problems.