I’m one step further… It appears that the webcam function does NOT depend on the MTU settings as I have first suspected. However, it depends on the NICKNAME being used.
I’ve just (accidentally) fired up a webcam under my usual nickname and it worked. I tried with the other nick and it did not work.
Hmm… it remains to be shown what the difference is and where exactly the problems come from. For you folks out there with similar problems, my advice is: try another nickname… it may work.
Cheers,
–gandalf.