"Cannot send files because .. is using chat in Gmail or is using another chat program" while non of these is the case

[HBE]

Hi!

lately friends and myself are unable to send files: we always get the
message:
"You cannot send files because <name> is using chat in Gmail or is
using another chat program."

None of us is logged on in Gmail; none of us is using another client;
all of us are only using and logged on to the Gtalk-client.

So i simply fail to see what might be causing it .. but it surely is
veryvery pity sending files doesn't function at all rather suddenly.
(it DID work like a charm - and as far as i can detect truly nuffin
has changed since)

If anyone knows the answer .. i would be grateful !

Thanx in advance,
HBE