Not sure about automated tools, but the first thing I'd do in this situation is run up RegEdt32.exe and look at HKEY_CLASSES_ROOT - at that point you should be able to see every COM object, and that will give you the ClassID. You can then look those CLSIDs up in HKEY_CLASSES_ROOT/CLSID to find the typelibrary GUIDs. It's a manual approach but it should tell you all you need to know about clashes.
Another thought, maybe they're both sharing a common based DLL. You can check this using Dependency Walker
