For now I'm giving up, but I'll have to "refresh" this thread in future ;-)
The last thing I found out is that entry that I marked in previous mail as "LAST VALID KEY/VALUE PAIR" is the problem - it is fine itself, but it "breaks" the stream somehow. Removing it fixes the problem, but I still don't know why. Its token is completely "normal" - 5664330507961197044404922676062547179. No other ideas on how to push the investigation further though :-(
M.
