GPO not being applied all the time.

We are running a Win2k Server with about 30 Win2k Pro Clients. There are approximatly 10 GPO’s being applied and Manditory Profiles is in effect. The Profiles are approximatly 500k in size. Here’s the problem. Logging onto a workstation would sometime take 1 to 2 minutes compared to 10 Sec when working properly. And when logon is slow (1 to 2 minutes) None of the GPO’s are applied. Here’s what I do to temperaryly resolve this problem. I log onto the workstation with admin account and release ip and renew ip. This procedure will reslove the slow logon time and thus, the GPO’s will apply when users log onto the workstation. Rebooting the workstation will sometime work but not all the time.

Could someone provide me with an explanation as to what can be the cause here.

Thank You.