I'm not sure if I understand what you're saying Doskabouter. I couldn't find the configuration option, where is it exactly ? Also I now just press enter on an 'uitzendinggemist' stream and it shows 6 options (like mov std, mov bb etc). I'm not sure what you mean with 'press play' ? When I right click a video it does have the option 'play with', is that what you mean ? But even then, it shows again the 6 options. Anway, again, thanks a lot for this great plugin, really love it !
The configuration option is in Mediaportal configurations/plugins/onlinevideos/sites.
There, select uitzending gemist, and then you'll see a "prefered quality"