Terry,
I've built a ton of COMs and never unregister them prior to kicking off the BUILD DLL/MTDLL command.
You will have issues if different machines compile the COM because different CLSIDs will be created. When you take that to the web server you'll have to uninstall it from MTS and reinstall the component.
I'm not sure if it helps to copy the DLL to machine2 and register it before doing a build from machine2 if it'll keep the CLSID from getting hosed up or not. If you are doing all the builds from a single machine it shouldn't be a problem.
>When my project builds an OLEPUBLIC COM it goes to the register. Do subsequent builds, providing the COM name is reused, use the same CLSID, or should the old version be removed with "regsvr32 /U " before the new one is built.