The RPC server is unavailable - Error 1053 - 1058 - 1030

I am using a domain with 1 domain controller and 2 terminal servers. All of them are running Windows 2003 with SP2. There some some problems with users that cannot logon to the terminal server with error "The RPC server is unavailable". At this time, the users who ar logged on in this server are able to work normally and can connect there data on the domain controller or data server. After this occurs, it is possible to logon to the 2nd terminal server but after sometime the issue is solved automatically. I even tried to change the "Disable NetBIOS over TCP/IP" settings to "Default" but I am getting the same error.

Event Type: Error
Event Source: Userenv
Event Category: None
Event ID: 1053
Date: 5/11/2008
Time: 13:13:29
User: NT AUTHORITY\SYSTEM
Computer: SRV02
Description: Windows cannot determine the user or computer name. (The RPC server is unavailable. ). Group Policy processing aborted.

Event Type: Error
Event Source: Userenv
Event Category: None
Event ID: 1030
Date: 5/11/2008
Time: 13:00:59
User: NT AUTHORITY\SYSTEM
Computer: SRV01
Description: Windows cannot query for the list of Group Policy objects. Check the event log for possible messages previously logged by the policy engine that describes the reason for this.

Any help would be appreciated.

You need to ensure that you use domain internal only the domain DNS server on the NIC, you should not use external ones. Also check to ensure that the computers are not multi-homed with different ip address. After that you can run dcdiag /v, netdiag /v on your DC to check for any errors.

If this problem is happening alternatively after some specific time period, then check to see how bad the resources on these TS's are depleted. It could be simply be the system just is unable to process the request inthe time frame defined. You can try to run perfmon or some of the monitoring system and check if cpu, memory, etc; are consumed.