After setting up a SVN server at MediaTemple I tried to access it with TortoiseSVN. It kept on asking for passwords even though I’ve entered in the correct one.

1. TortoiseSVN will ask for passwords multiple times depending on the number of different domain folders.
2. Upgrading to the newest version of TortoiseSVN [TortoiseSVN 1.5.6, Build 14908] solved the problem of the program crashing.

Setting the SSH client property stopped the multiple password checks.
C:\Program Files\TortoiseSVN\bin\TortoisePlink.exe -l username -pw password