I did around 4 or 5 complete installs during the weekend, including another two I did today. The result so far has been unchanging. On the plus side of it, I can at least use Asterisk to make calls again, but I don't consider this a good trade off :-D
Anyways, so far I did notice, that there is always a problem with downloading v4l2...I see a corresponding message everytime when I reload router.
So far I was able to scan for channels with my nova hd-s2 card...but really watching TV seems no longer possible.
I would really appreciate, if someone more knowledgeable than me could help me getting mythtv to get working again.
PS: stupid me...I forgot: running 1004, net-install