Version: 4.3 (using KDE 3.3.2, (testing/unstable))
Compiler: gcc version 3.3.6 (Debian 1:3.3.6-7)
OS: Linux (i686) release 184.108.40.206
If you keep clicking the same word about twice a second, the selection will move downwards until it hits the bottom and kwrite crashes. No text is moved, only the selection.
If you need further explanation or maybe a screenshot, feel free to email me or contact me at Freenode, my nick is ArcSine.
The crash part was fixed by cullmann, see:
There is still strange cursur movement though (tested with: KDE 3.4.1).
*** This bug has been marked as a duplicate of 106402 ***