Well had I known the problem could lie there it would
have taken me
five minutes to fix instead of hours. Now I know a little more about
USB.
USB hubs in general can really be a pain. I have had two of them which
didn't work properly; I always thought OK, it's caused by the linux
kernel who is very restrictive concerning device behaviour. It only
worked well for mice and printers. I had probs with USB audio, camera
and scanner.
One day I used one of them at a windows XP box - and got a blue screen.
My recommendation: Avoid devices which are labeled as "For home and
small office use only".
Meanwhile I found one which really works well in any occasion and am
very happy with it because it behaves as desired: I don't recognize
that it is there :) .
Best regards
ce