Comment 4 for bug 874734

That is very strange, cause I get the same results on two systems now. When you press Alt-backtick, make sure you hold Alt key for about 2 seconds, then hold backtick (`).

Also another way to see the key press is by doing:

Alt-Tab, continue holding Alt key, release Tab, then press Backtick key. You will see that the switcher response by replacing the application icon in the switcher, with a preview of the application window.

If you still need confirmation after this, I can try an do a video.