Dear Bjoern, dear Dimitris, thank you for your bug reports! I ask you for a favour:
Could you please try Gajim from Debian experimental? The plugins for the new Gajim are in experimental, too, if you need them. I'm not yet sure, whether I will fix this bug in a new Gajim 0.16.8-something, because IMHO Gajim 0.16.11-somethingelse already works very fine for me. If the new Gajim works for you as well, I would do the next upload to unstable instead of experimental. Thanks in advance! Cheers, Martin