Problems with TortoiseSVN and authentication (on WinXP)

Newer versions of TortoiseSVN may produce errors when repositories reside on servers with unknown (untrusted, whatever) certificates. The very same repositories may be checked out and updated using a command line version (or with Mac tools). The error message may be a little too short and doesn't explain very much:

Update
OPTIONS of 'https://my.server.com/my/repository': SSL 
negotiation failed: Secure connection truncated (https://my.server.com)
Finished!

In order to fix this, you will have to change the underlying method of subversion/Tortoise for communicating with the server. This has to be specified in the server settings. This is a simple text file, hidden somewhere on your system. The easiest way of locating this file is by opening the Tortoise Settings and edit the "Subversion configuration file" (found under "General"). However, this only opens the "config" file, but what we need is the "server" file -- which luckily can be found in the very same folder as the "config" file. On my german Windows XP installation, its path is C:\Dokumente und Einstellungen\userid\Anwendungsdaten\Subversion\server. In "server" (pay attention to not accidentally add a ".txt" when saving the file), add a new server group in the group section, and set the http-library to "serf" for that group. E.g.,

[groups]
myserver = my.server.com

[myserver]
http-library = serf

Now, TortoiseSVN should work with your server.

P.S.: I found the solution at http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=507374 (although I have no debian system, it solved my problem, so thank for the tip, Peter Samuelson) ;-). I adapted the solution for TortoiseSVN, as it fixes the problem with TortoiseSVN, and most TortoiseSVN forums suggest to downgrade to elder TortoiseSVN versions, which didn't worked in my case.