Proxy 4.02 goes to 100% on CPU

I'm running Proxy 4.02 on a Windows 2000 server. Several times a week we'll get calls that users can no longer browse the internet through the Proxy. In looking at the proxy server I find that the "proxyd.exe" process is stuck running at 100%.I have to stop and restart the proxy service to get things working again.

Does anyone have any ideas why this is happening?

[381 byte] By [robs88] at [2007-11-14]