Intermittent 'Could Not Reconnect All Network Drives' on one drive

Hi

Users on XP workstations experience this error 2-3 times per week, always on
the same drive (other drives are fine). When they reboot, the drive maps
fine. Drives are mapping from a script on the server.

This problem appeared after an upgrade of the server from NT4 to 2003. The
default policy was also modified for password expiration.

Troubleshooting I did:
1. Pointed workstation's DNS to domain server only (server forwards to ISP
DNS)
2. Removed permissions on the directory and put them back.
3. Disabled fast logon on workstations
4. Tried putting the users in the local group instead of the global group.

any help appreciated. thanks