Windows XP Login Scripts

I am having trouble getting my login scripts to run consistanly on my Windows XP Pro clients logging into my Windows 2000 servers. It seems that thry will work about 50% of the time.

Running Windows 2000 Server(all service packs)
Windows XP Proclient
Using group policy editor to assign the scripts

Not sure what other info is relevant. Some machines work fine, others have problems.