QueryInterface for interface error

Question

I have a windows service application that calls a VB6 COM component that I wrote that serves as a wrapper to another set of COM objects. I am running the windows service under a domain administrator, and obviously the domain administrator is administrator of the local box where the windows service is running. I keep getting a "QueryInterface for interface EXEImp._CEXEData failed.", where EXE_Imp._CEXEData is my VB6 COM object that I have created. I have searched the web and found that the problem could be security related, but that's what I don't understand because I am running this windows service under a domain administrator. Any clues and/or suggestions?