Scott Hanselman posted some of the pains of interacting with ASP, ASP.NET and COM. If you have the time read through his post and the comments, to get a better understand of the issues he encountered.
A while back, I've a similar post about dealing with two CLR versions and COM interop. Also worth checking out...
Quick Poll: How many of you out there are using Classic ASP and ASP.NET in your web environment?