If you have a Windows XP SP3 or Windows Server 2003 SP2 machine that goes really slow for GPO application (like tens of minutes or even hours) and the network trace looks something like
I.E. Read AndX Request and Response with small values like 2-4 bytes over and over again until it gets through the whole registry.pol file.
Then look at KB319440 (http://support.microsoft.com/kb/319440) and apply the registry change for BufferPolicyReads.
