after renaming our AD Domain, the reinstallation of SMS didn't succeed.
WSUS wasn't working anymore.
My research lead me to the following KB(913441): http://support.microsoft.com/default.aspx?scid=kb;en-us;913441
The source of our problem came from IIS (which explain why WSUS stopped working on the server too).
I contacted MS to get the fix, it worked great on our server.
Contact me if you need the patch