Group Policy Issue

Hi,

Upgrading our workstations to WinXP from Win2K. Have a test machine in
my office to see how it would handle our standard hardware. As part of
the test I had a GP to install Office and apply some settings. This all
worked fine.

A couple of weeks down the line and when I try to do the same setup on
another PC, the GP cannot be applied. And am now getting the same
problem on the machine it used to work with.

In the logs, I am getting an even 5719 from NETLOGON, and also 1054 from
userenv; both related to not being able to find domain controllers.

I am completely lost as to why this is suddenly happening. The Win2K
machines are fine and pick up their GP with no problems. It is the fact
it worked once with XP, but now refuses to work that is really annoying
me. And I have tried rebooting both our DCs (both Win2K3 Server).

Any hints greatly appreciated.