Sudden Domain Failure: domain is not accessible.

I have 2 DCs in a domain together. The primary is a SBS 2003 server and it’s accomplice is a regular Win2k3 server. Everything has been working smoothly. Then today, I get this message:

“ is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. The list of servers for this workgroup is not currently available.”

I don’t like this error message for a few reasons:

1. I AM the administrator, I DO have permissions. (I hate when M$ tells me to contact the admin when I am logged in as the admin.)

2. It says the workgroup is not available and this is clearly an AD domain.

3. I don’t know what causes this or how to stop it.

Funny thing: I can browse all the shares on the network if I type the path directly, no problem. The error only shows up when I try to browse from Network places, I can no longer get the list of computers on the Domain. My mapped drives work fine. Terminal services work fine. There are no DNS errors, or any other errors on the server event logs. I have no local errors in the event logs.

Help?