Secondary DC’s dont work?

Have a Win2k domain with the master DC and 2 others for backup DC roles. As a test I dropped the master DC to see if the other 2 would pick up as they should, well they didnt at all. Everything from email (exchange 2003) to login\internet access was dropped until I rebooted the primary DC.

I researched the web (technet, etc) for any whitepapers on this but didnt see anything specifically… any ideas?