CentOS | Windows 2008

I've got a CentOS 5.5 server running nfsd. On the Windows side, I'm running Windows Server 2008 R2 Enterprise. I have the "Files Services" server role enabled and both Client for NFS and Server for NFS are on.

I'm able to successfully connect/mount to the CentOS NFS share from other linux systems but am experiencing errors connecting to it from Windows. When I try to connect, I get the following:

C:\Users\fooadmin>mount -o anon 10.10.10.10:/share/ z:
Network Error - 53

Type 'NET HELPMSG 53' for more information.

(IP and share name have been changed to protect the innocent :-) )

Additional information:

• I've verified low-level network connectivity between the Windows client and the NFS server with telnet (to the NFS on TCP/2049) so I know the port is open. I've further confirmed that inbound and outbound firewall ports are present and enabled.
• I came across a Microsoft tech note that suggested changing the "Provider Order" so "NFS Network" is above other items like Microsoft Windows Network. I changed this and restarted the NFS client - no luck.
• I've confirmed that the share folder on the NFS server is readable/writable by all (777)
• I've tried other variations of the mount command like: mount 10.10.10.10:/share/ z: and mount 10.10.10.10:/share z: and mount -o anon mtype=hard \\10.10.10.10:/share * No luck.
• As per the command output, I tried typing NET HELPMSG 53 but that doesn't tell me much. Just "The network path was not found".

I'm lost on how to proceed with troubleshooting. Any ideas?