Using vb6 dlls in asp.net

Hi,
i have a large set of vb6 dlls that i have to use in my asp.net application at runtime, the dlls are a set of reports a report making tool and report viewing tool, the reports use the clases of reportmaking tool to set report parameters, the report viewing tool displays the results from the reports, i have directly referenced the reportmaking and the report viewing tool but i have to bind the report objects at runtime, i have succesfully created the objects for the reports but when it's object calls a method from the report dll's class it gives me the following error

System.Runtime.InteropServices.COMException: Type mismatch


i have been working out on the problem with no success, any help is kindly appreciated, Iam using vs.net 2002