I got my official RaspberryPi-touchscreen up and running.
Installed Raspian and Kodi.
Raspbian works well, but Kodi got me some resolution problems.
It detects the Screen to be 720x480 instead of 800x480.
After starting it, there always are 80 pixels on the right hand side which keep the content displayed before (e.g. Raspian or some terminal lines).
Changing config.txt influences Raspbian while Kodi keeps it size. That's why I believe Kodi gets it's resolution directly from the display's driver.
Does anybody have a similar problem or a solution for me?