Youtube steals focus, can't use Firefox 13.0.1 shortcut keys

Browser shortcut keys like ctrl+tab and ctrl+w won't work after I click on a youtube video. Instead the video steals the focus and sends the command to adobe flash it seems.

This problem persists even after clicking elsewhere on the page. To resolve it, I have to click on a different application, or a different tab before coming back to the youtube page.

Any way to fix this?