IM system problem

Diane, perhaps you can point this out to the webmaster.
(you know, the guy which everybody needs 365 days a year but that never gets the credit for it; only complaining grumpy employees on monday morning )
I have tried to use the Instant Messaging system a few times now; it seems to me like a useful feature. The first few lines seem to go ok, though I get the feeling the respond is delayed.
But after continuing the conversation with a few lines I don't receive a respond; though I'm positive the other person is answering.

And the weirdest thing of all; sometimes I get the answer of the other side... but a week later, and the IM window pops up out of nowhere whilst I was logged in all the time .

I've heard other members experiencing the same so I guess it's a bug in the software code but perhaps I have to tune my firewall !?

And one other thing (I really don't want to nag); I've tried to consult the search function; but it has never returned a single result.. even not when narrowing the search down to "the" (believe me - I've tried)