Version:           1.2.3 (using KDE KDE 3.5.4)
Installed from:    Ubuntu Packages
Compiler:          gcc version 4.0.3 (Ubuntu 4.0.3-1ubuntu5) Target: i486-linux-gnu, Thread model: posix
OS:                Linux

The bug occurs when one is using Kontact f.e. KMail, and during the usage the  /home partition runs out of diskspace. KMail then tries to write something without checking if there's any space left and crashes.

How to reproduce:
Start Kontact, activate KMail
Fill up the diskspace of the /home partition, for example like this:
takis@issaris:~$ dd if=/dev/zero of=justzeros
dd: writing to `justzeros': No space left on device
8977+0 records in
8976+0 records out
4595712 bytes (4.6 MB) copied, 0.292418 seconds, 15.7 MB/s
Use KMail, for example, click on several different folders. After clicking on a few unread maps, Kontact crashes.

There appears no DrKonqi, but KNotify does appear, showing this:
http://static.flickr.com/81/243816418_1d9449dd30_o.png