ALT+TAB loses focus

I often use ALT+TAB but sometimes, not always, after 0.3 secs it loses the focus on the newly switched window. No arrow on the right of the icon in the launcher, no name of the app in the top-left corner, no cursor active, but I see the correct window and the previous one is in the background.

This happens with any window, often I switch between terminal and Aptana (so I press ALT + TAB), and there's no shortcut assigned to ALT itself. Anyone has any idea what could be wrong?

Thanks

It's a unity bug:

https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1035628

Your best bet is to wait until an update comes through fixing it.

I was frustrated with this too, and I'm noticing that once Unity is in this confused mode it affects more than Alt+Tab. Clicking the title bar of the other application to switch can also fail. One workaround there is to click in an editable area in the target window.

Following the link that roadmr posted, I see it mentions that pressing Alt+Alt right after Alt+Tab works too. And that's more convenient: "a workaround, or a recovery, is to tap Alt twice. After raising and dismissing the HUD, I always find the top window back in focus."