Comment 9 for bug 34707

I know it doesn't seem very related, but the 'screensaver starting with SDL games' bug on gnome bugzilla was marked as a dupe of that one, and there is a patch which says:

Updated patch for 2-14. This is already in HEAD.

Note, these changes also fix the problem where the warning fade-out occurs when
playing fullscreen games. In that case the game grabs the keyboard so the
screen can't be locked so we shouldn't do the warning fade at all.

This sounds like what is happening here.