remote assistence

[Harry]

Hi,

I am working with a local netwerk, a US Robotics 8000A-2
router. The firmware is upgraded to 2.5 so the router
should support uPnP. So far so good, but usually I can't
get remote assistence to work. Even not from 1 computer
to the other inside my own netwerk. I tried all messenger
versions. Sometimes it works, sometimes not. Not
depending on anything I can figure out. I have no
problems with video conferences etc. All computers use
Windows XP professional with SP1. Firewalls are sometimes
used en sometimes not (Zonealarm 3.7). Also this does not
make any difference.

Anybody any idea how to solve the problem?

Thanks in advance.