Can not browse Windows 2003 network

I recently upgraded NT 4.0 network to Win 2003. I have 2 domain controllers at 2 different locations. I can not go through Windows explorer and browse the full domain. From our NJ location I only see NJ systems, from NY only NY systems. Before the upgrade you would see both. You can ping across locations, map drives, use shortcuts, etc… The only thing that doesn’t seem to work correctly is not able to browse and see all servers.