The screen is flipping because the Game is PAL....boot an NTSC game and it wont do that :-)
Tisis one of the reasons why I a such a big NTSC collector and reject PAL whenever possible.
NTSC flickers less, and scrolls smoother (60hz vs 50hz)
if the Plasma has a V-HLD control in the back (Highly doubt it) then you an also display PAL.