Go to Control Panel->Administrative Tools->Component Services.
Expand Computers, then My Computer, then click on DCOM Config. Under the View menu, select Detail.
In the right pane, you should see a list of DCOM stuff with Application IDs. You can’t sort on App ID, but you might be able to find the one listed in the error(s). That should point you at what service it is.
If it is the JIT debugging, there should be an option to disable it in the Visual Studio options somewhere, which will probably be a cleaner way of disabling it. (Last time I looked for it was VS6 though, I’m not sure about 2003 or 2005.)