For your information, it was really one of the MS security updates released in August (namely, the fix for MS10-047) that caused this issue.
Interesting indeed, I guess that's what happens if you rely on undocumented stuff. At least it was written sufficiently defensively so that it didn't start crashing or something...
![Wink ;)](https://forum.avast.com/Smileys/default/wink.gif)