Actually it looks like the program did nothing -- notice that it says "0 fixed". The message saying that Alt+tab should now work correctly looks overly optimistic.
The reason it didn't fix any windows is that neither of them are 0x0 windows. Kaspersky might still be the problem, but since it's not a 0x0 window I don't dare mess with it.
You might as well report this issue to Kaspersky, because having a full-screen always-on-top window is weird and evil. They should fix that.
However the Alt+tab bug is ultimately still a bug in Windows Explorer, as far as I can tell. It is *extremely* disappointing that it still exists in Windows 8.1.
I could tweak my Alt+tab programs to zero the visible flag on Kaspersky's window, but I'd rather not. The source code is available for anyone who wants to try it. VS Express should build it just fine.