Called the Care Center to check for the current status.
The repair of my Nokia 808 was finished today. I should get my phone back by the end of this week.
All I know so far is they replaced a circuit board... maybe the delivery note contains more details about what was fixed, I will keep you posted about it ;)
I didn't mention last time, that I sent my E7 in together with my 808.
(There was a problem with my warranty at first, so I had to send it in again)
Maybe the E7 users of my CFW remember, that the USB connector was broken and therefore the phone could not be charged anymore.
It is still in repair, but should be back fully repaired by the end of next week.
Let's see if Nokia really is able to fix the 3G bug, I am looking forward to get it back :)
Edit:
23.11.2012/Friday, no post package today... I guess I have to wait for Monday :(
Edit II:
I was wrong, did not see the pickup note the mailman left in my post... my 808 is back!