Missing Home Folder XP Clients 2008R2 Domain

We just completed a migration from Server 2003 to Server 2008R2. Everything seems to have gone well except that many of our desktops have stopped mapping the Home Folder as set in Active Directory. Other mappings that are defined on individual clients are mapping just fine, these mappings are all on the same file server as the failing Home Folders. Half of the users are on 1 file server and half are on another. Users from both servers are having this problem.

I have enabled the Group Policy setting to "Wait for network before logging in". I enabled the policy to "Run Logon Scripts synchronously".

There are no errors on the Domain Controller or either File Server. When I enabled Group Policy Preferences as an attempted workaround, I get this error:

The user 'V:' preference item in the '<Policy Name>' Group Policy object did not apply 
because it failed with error code '0x800708ca This network connection does not exist.' 
This error was suppressed.

This seems to indicate that the network connection is not ready by the time Group Policy is processed. But isn't this the point of the "Wait before logging in" and "Run Logon scripts synchronously" settings?

Some other background facts:

1. The new Server 2008R2 installation is a Virtual Machine.
2. It is on a new Subnet in a different building from the old server.
3. DNS and DHCP were also migrated from the old DC to this new DC.
4. These Home Folders were all working properly before the migration.

Are there new security restrictions/policies in Server 2008R2 that might be causing this? Is there a way to check whether I have an underlying network connectivity issue? Maybe moving the server to the new building is causing a delay/timeout?

Any thoughts or ideas on what could be causing this or how I can resolve this?

Thanks.

This was an outdated client antivirus/firewall issue. Our version of Panda for Business was about 9 months outdated. Updating the server and clients has resolved this issue.