why do i get combing/shimmering on my kv-30hs420..............

I have a ps3 connected via hdmi to my kv-30hs420 and when playing some but not all ps2 games and ps3 demo games on the ps3, why do i get combing/shimmering ingame when moving the camera in a fast motion left and right/horizontaly?

Thanks....

It's an interlaced CRT and I believe it converts everything to 1080i for display.

The only way to prevent this is probably to either set the game for 480p (which the display may give you the option of displaying as 480p or 540p instead of 1080i), or lower the frame rate of the game so both fields of the 1080i image come from the same frame. Any game running at 60Fps will do this on an interlaced display.