Hardware scanning

I am having an issue with hardware scanning. I am running the software on our network that has 2 domains in it. I have already scanned the systems within the domain that has the Service Desk server in it. But I am getting very spotty results on the domain that is sharing the wire with it. I have a few of the workstations scanned using the Network scan, but I am getting about 75% failure with the error:
"Either access denied for the user or the remote DCOM option might be disabled in the workstation."
I am getting the IP's so I know it sees the systems. I have tested with one of the "failed" systems. I logged in with that domain's admin (which is set in the network scan) and made sure it part of the local administrator's group (put it there specifically for the test) and made sure DCOM was active and still it fails. Any ideas? These are W2K systems.