Which device are you using? The N9 has an OLED display and these displays don't have the burn-in problem.

I've also found a small bug where the timer on the 'playing' page keeps ticking even after the currently playing item has ended. When I'm watching a 10 minute video the timer will keep running after it reaches the endtime. So it just keeps counting 10:01, 10:02 and so on, while the duration is correctly displayed as being 10:00.

The timer also seems to be off for about 20 seconds after seeking. When I click in the progressbar to seek the progressbar is about 20 seconds off with the time displayed in XBMC. So the timer in the app is displaying 10:00 while XBMC displays 10:20.

Both are some small annoyances which don't have a high priority. I might even try to fix them myself and will send you the patches.