Win2k Pro - IP services locking up

Archived from groups: microsoft.public.windowsnt.protocol.tcpip (More info?)

Have a win2k pro machine as our phone server. Sitting behind a sonicwall with a fractional t1. This server is identical to numerous other phone systems we have out in the field, but for some reason about every 5 days the IP services lock up. The IP phones can't see the server (on the LAN or WAN), and PCAnwhere won't connect. I can ping the server, and also can use the server locally no problem. The phone system responds fine to non-ip phones, but can't see the IP phones... Have NO idea what's going on.
Norton system works was installed, but I didn't like it so I pulled it off. Panda Antivirus is on it now and is really the only service running besides PC anywhere and the voicemail software.