Hello Mr. Thomas,
sorry but I do not speck german.
Anyway, I found your post with google, looking for the same problem!
Since 2 months I have a MacMini mid 2010, wich is a Core2duo 2,4GHz anc Nvidia 320 graphic card.
Since the very beginning I got the same problem you claim.. BLU screen every time the monitor "wake up", and this is very frustrating. Sometime I had to wait up to 20" before to get stable video! Damn bad!
I've used 10.6.4, then 10.6.8 then 10.7 and 10.7.1. OS, no improvement.
Here not Apple nor Nec could help me.
Have you find any further information since your post?
I look forward for your kind replay.
Viele danke und Gruessen!
Pierluigi