Thanks for the suggestions but none of that helped. There is clearly something in this program that is causing serious disruptions in TCP traffic in and out of this workstation. There's no software firewall, there's no errors or blocks being reported on the hardware firewall (Cisco PIX 501). I'm using the latest java engine and latest Limewire Pro. When the connection drops it brings down all communication for the PC, including other processes running TCP across the intranet or internet. I've tried three different versions of Limewire, including the PRO. Same results occur when trying to download 2 or more files simultaneously (up for 2 minutes, down for 1 minute, up for 2 minutes, etc.)

I can't imagine I'm the only one who experiences this. The only thing I can think is that Limewire is not compatible with Windows 2003 server. I suspect that OS is not commonly used. I'll have to try it on another PC running XP and report back what I find.