EL6 mount.cifs and Windows Server 2008 R2

A project related to mine is pushing ahead with rolling out Windows 2008R2 into production. Right now, it seems to be creating compatibility problems with filesharing between these new hosts and our EL6 systems that want to use CIFS to pull files from those servers. From Googling about, it appears that Windows 2008R2 ratchets up the dial on the security-settings for CIFS authentication. Result: doing a mount -t cifs -o domain=DOMAIN,user=USER "//win2k8r2srvr/share/" /mnt/cifs gives a permission denied (errno 13).

Upping the debug level on the connection-attempt indicates that cifs is trying ver=1 (the mount.cifs man pages indicate this is vanilla NTLM). I tried altering the security mode used by the Linux client (tried ntlmv2, ntlmv2i, ntlmssp and ntlmsspi - even tried krb5), which only resulted in changing my error code to a 95.

Not able to tackle it client side, I tried altering settings at the server. I tried the fixes suggested in in http://support.microsoft.com/kb/957441 and http://technet.microsoft.com/en-us/library/cc960646.aspx, but saw no joy from those tweaks, either.

Anyone run into this and found a fix?