Since day 1 videos in Firefox don't go so well on the ZF10 when hitting the full screen button. This often crashes the browser and when it's started again the app is only shown on the top half of the screen, as if the entire app has been shifted up. The only way to fix this is to close the browser entirely and start over. This happens about 80% of the time.
This can easily be reproduced on most websites with video eg youtube. None of the firmware updates have fixed this so far.
Sure here you go.
Tapping full screen in the video briefly rotates the screen and then the browser app simply disappears. The screenshot is what it looks like when I start Firefox again. Only closing it (swipe it up and away in the app overview) makes Firefox behave normal again.