I'm trying to debug an interface leak in a component (registered as threading model= "Both") that is being used within IIS and stored in the Application object. If I use component when compiled without _ATL_DEBUG_INTERFACES defined there is no problem

However, if I define it, when my app loads via global.asa, I get the message:

Cannot add object with apartment model behaviour to the application intrinsic object.

Any ideas what might be happening?