@adrenaln: hmm, I can remember, that I actually didn't have this issue until a certain point (RC5 or so)...
Although I believe that this is not a CF issue, HiJack is somewhat right that this issue could have been triggered by a windows update; even tough I do not have a persistent internet connection in the car i sometimes did windows updates via WLAN when I was at my home base...
I will do a fresh windows & CF install this weekend, so i can see than if this was caused by an update or not.