Clustered SMB shares from Windows Server 2008

Is anyone using clustered SMB shares from Windows Server 2008? We are currently having huge problems connecting to these with Mac OS X clients (10.4.11 and 10.5.4). Other shares are working perfectly but these 2008 shares are giving me a major headache. When connecting (cmd-K) to smb://serveraddress/ we get an empty list of available shares. When using smb://serveraddress/share we get an error that the volume could not be mounted (with error code: -6602). Shares can't be browsed from command line either. The only thing that has helped is to compile and install the latest Samba by hand. After that I'm able to browse the shares with smbclient but anything with GUI is not working. Is there something that could be done from the server side? Any other suggestions?