This post http://www.internettablettalk.com/fo...&postcount=304 gave me a lot of clues.
I had deleted the documentation, for instance. Also apt-get wasnt working for me after the update.
So I ended up reflashing. The SSU update is now also available via flash, so theres no need tu do any updates after that. I am installing most of my programs as we speak.

This is the second time I had to reflash after an SSU.