domain controllers

hello, i'm relatively new in working with domain controllers and am experiencing trouble with replication between my windows 2000 and 2003 domain controllers. I've run dc diag and the following tests are filing:

Starting test: Services
NtFrs Service is stopped on [SERVER]
......................... SERVER failed test Services

Starting test: Advertising
Warning: DsGetDcName returned information for \\server, when we were trying to reach SERVER2.
Server is not responding or is not considered suitable.
......................... SERVER2 failed test Advertising

I have thus far been unable to find a solution to these problems. Any help or ideas would be greatly appreciated.