Connecting to SMB share on W2K or W2K3 using a CNAME

Apply the following registry change to the file server to which you installed the hotfix. To do so:

a. Start Registry Editor (Regedt32.exe).
b. Locate and click the following key in the registry:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanServer\Parameters
c. On the Edit menu, click Add Value, and then add the following registry value:
Value name: DisableStrictNameChecking
Data type: REG_DWORD
Radix: Decimal
Value: 1
d. Quit Registry Editor

http://support.microsoft.com/kb/281308