Could be a lot of things GPO permissions, DNS, network, to name a few
Take a look at these two articles
http://support.microsoft.com/kb/887303
http://www.experts-exchange.com/articles/OS/Microsoft_Operating_Systems/Server/2003_Server/Diagnosing-and-repairing-Events-1030-and-1058.html
Good EE article by Chief IT
I'd try the dfsutil /purgemupcache first and see if that helps (i've had luck with it on a few boxes in the past)
Thanks
Mike