An object call caused an exception.
(IID: {51372AEF-CAE7-11CF-BE81-00AA00A2FA25}) (Method: 3)
(Microsoft Transaction Server Internals Information: File:
i:\viper\src\runtime\mtxex\activity.cpp, Line: 889)
(Exception: C0000005) (Address: 0x71101ab8)
MSXMLR + 0x1AB8

This dll used to work OK, the only thing that changed is a new Class Module
that is not even referenced yet in the ASP code.

What could be causing this ?

Hi,
I think you need to reregister component in MTS (delete objects in MTS
console and register component from file)
It is posible if you add class module with instancing property set different
to private
Tomasz B.