SP2 included some network fixes too. Did you have any reason not to get the fixes?
Customer has a small 3-computer peer-to-peer network. all computers run xp pro sp1. Had been operating fine with shared folders on one machine. Lately other too amchines "access denied" to shares. Found that on host computer, Control Panel -> Adminstrative Tools -> Local Security Policy, "Access this computer from the network" had no user names listed. Added Everyone and the other two computers accessed the shares immediately.
However, if the host is rebooted, or left to run for a while, the user name disappears from the host's "Access this computer from the network" and the other two computers cannot reconnect. Need to start over again.
Any ideas? Am I missing something when I set the user name or is someone aware of a virus, work, etc. that might be doing this. Any suggestions appreciated.