Incremental upgrade from 6.0 to 6.0.1

I downloaded the incremental upgrade (c49ngna.exe) from 6.0 to 6.0.1 for WinNT/2000 from IBM Passport Advantage website and tried to upgrade my Domino server (messaging only) without success. The error message was incorrect release. I am at loss to this error message. It seems to me everything is correct. Have someone encountered similar issue and share your solution with me?

Thanks,

Ray