JSI Tip 1317. After SP4, you receive an Access Denied when acessing a UNIX computer using DNS.

SP4 turned off host name mixed case preservation to comply with RFC 952.

Upgrade to SP5 and use Regedt32 to navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DNS\Parameters

Edit or Add Value name CasePreservation, as a type REG_DWORD and set the data value to 1, True. The default is 0, False.