Network Name No Longer Available – Win2K

Copy a large (5Gb) file between Win2K server sp2 and Win NT 4 sp5. After copying has been going on a while, an error comes up “The specified network name is no longer available.” MS article Q255678 discusses this issue, and references Q161372 re: SMB Signing. Question: I have never explicitly turned on smb signing…my NT 4 servers don’t show EnableSecuritySignature or RequireSecuritySignature values in the HKEY_LOCAL_MACHINE\system\currentcontrolset\services\lanmanserver\parameters key. These articles indicate that, if smb signing is enabled, this problem will present itself. Has anyone experienced this problem, and is there an easier fix than modify-the-registry/reboot? TIA for any help. Russ.