Version: (using KDE 4.2.1) Installed from: Debian testing/unstable Packages Filing as bug as the normal user (i.e. my girlfriend) does not know what's up. She just hands me the laptop and tells me "it's broken". You can't log in if the home partition is full or your quota is exceeded. Possible solutions: 1) Display a warning which at least informs you of the situation 2) Log into a minimal mode (But do _NOT_ lose session state like openend windows, etc!) 3) Log into a Dolphin session so the user can delete stuff. I am sure there are other solutions, as well :)
As you can not log in any more, this issue is major at least. Maybe even critical/grave.
*** This bug has been marked as a duplicate of bug 81653 ***