What is causing this in X-Plane?

[immortal 0]

Hi,Why am i getting these purple lines and smudges when playing Xplane 9.62?Im using a 27" imac with i3 3.2ghz, 4gb ram and ATI 5670 512mbAlo the bottom image says something about a driver at the bottom. Am i getting hardware acceleration?The above part blown up.... Matt

[immortal 0]

Anyone?

[TechguyMaxC 516]

That's color banding, a classic sign of low color depth. Check the game to make sure it's running in 32-bit color. Also check your graphics settings via your driver's control panel.