You might want to look at using the GPMC. It helps a lot understanding how your GPOs are setup and interacting.
Dont know much about the way the GP is set up as it was all set up by my predacessor and I have not really had the time to look through how it was set up . He did nt document anything either which makes it all the more annoying.
This is likely the problem. Do you use any folder redirection at all?
Do you have roaming profiles? Yes
Is the 2k3 server a domain controller? If it is, did you do the AD schema updates when you brought it online?
Is your server 2000 or 2003? We have one of each but the main one is a 2000 server. We are in the process of migrating to the new server.
Is your windows DNS server the only IP listed in the clients DNS server list or are you using external DNS servers as well?
I tried the DNS entry on the client machine. It did make a slight difference but it is still far to long.