This bug seems to have been fixed in 13.10 with all updates, at least for me.
I've just used <Alt>+<Print Screen> and it correctly took a screenshot of the focused window (the HUD didn't show).
Also, pressing just <Print Screen> now immediately takes a full screenshot before the key is released, so the workaroung I mentioned in Bug #1231447 wouldn't work anymore.
This bug seems to have been fixed in 13.10 with all updates, at least for me.
I've just used <Alt>+<Print Screen> and it correctly took a screenshot of the focused window (the HUD didn't show).
Also, pressing just <Print Screen> now immediately takes a full screenshot before the key is released, so the workaroung I mentioned in Bug #1231447 wouldn't work anymore.
Could anyone else confirm this?