Logon Scripts Not Running for Users

I have NT 4.0 SP6 PDC and many BDC’s w/ same. Workstations range from Win98, Win2K, WinXP. We have logon scripts assigned to all users. Everything ran fine up until a week ago and I cannot think of anything that changed. Permissions on the Netlogon share are RX for everyone and security permissions are RX for Everyone. If I add any user to the domain admin security group the script will execute on a workstation at logon. As soon as I take them out of the administrators group the script stops running at logon.