Hi, Daniel.
I think it would be better to add a ok(0, ...) call at istream_QueryInterface() instead of adding new stub for interface we are not supposed to support. This function is actually incomplete, because it does not respond to ISequentialStream. If you want to test order of QI calls, just add another QueryInterface test implementation that does that, and reuse the rest of vtable.
Did you test with all versions, 3, 4, and 6?