Problems connecting to folders/files on Windows Server 2008

I just transferred all our files and folders to our new server which is running Windows Server 2008. The old server is running Win2K Server. When I browse to the folders and files on the new server from the desktop clients (all are WinXP SP2) some of the folders and files don’t show but they are on the new server. It doesn’t seem to be a permissions problem. I reset the permissions for all the subfolders in one of the users folders and some show and some don’t. It’s just strange. Anyone have any ideas what would cause this. I have Symantec Endpoint Security installed but this isn’t causing the problem as it still occurs when Endpoint Security is disabled.