hung processes server 2003

[Carina]

Any help appreciated on this one, its driving me nuts!

I have one site with a single w2k3 SE server and about 7 xp clients.
Every few days certain services linked to applications, namely a
synchronisation service for a CRM or symantec antivirus server just
stop working. The services appear as 'started' in the service
management console and running in task manager but arent actually
functioning. Any attempt to restart or stop the services fails and a
full reboot is required to get them working again. The odd thing is
that even a shutdown cannot fully terminate the hung service, this
gets stuck on 'closing network connections' for an indefinite period
of time and the only option is to power off manually (eek!). The
problem services start up normally and run for a few days as expected.

All networking services run as normal for all the clients, it just
seems to be these couple of applications that get stuck. When they do
however, explorer gets in a bit of a knot and can leave windows open
on screen or not close the start menu etc...

thanks in advance for any ideas!