Login Problems on Mac OS X

After upgrading to OS X 10.5.5, I could no longer log in to my main account. No PRAM zapping or safe booting, as suggested in many places, helped. Luckily I had another account with admin rights set up and found out that the source of the problem could lie the user's directory service entry. It needs to be deleted and rebuilt like so:

1. Delete the corrupted entry: sudo rm /var/db/dslocal/nodes/Default/users/short-user-name.plist
2. The user has now dissapeared from the user list in the system preferences, but its home folder (i.e. all the data) is still there.
3. To rebuild the ds entry, create a new user with the same short user name as the old.
4. You'll be asked if you want to use the existing home folder for the new user. Agree to that.

Of course I didn't find out about all that myself. It was all nicely described somewhere down in this post on Apple's discussion boards.