Problem with bluray playback

So I am currently using an LG PM6700 which I noticed something odd today. My blurays that support 24fps play back just fine. I have a few concert blurays that don't support it and playback seems jerky (at 60hz). I have turned off 24fps playback on the Sony bluray player and that doesn't change anything. All processing like trumotion is turned off. I tried using my PS3 instead and it behaves the same way so it is not player related. The strange part is that when I set the LG to game mode, playback is fine.

I am running my bluray player to my Denon 2112 out to the TV via HDMI. The Denon has no video processing. Pass thru only. Any thoughts. ??

My directv box outputs at 60 hz and it seems fine. Only happens with bluray discs. My old Panasonic plasma was fine but it only did 60hz as it was 720p. I am still within the return window so I don't know if it's an issue with the unit or if there is a reason for it.

Thanks in advance for any insight.

Both blurays are 1080i instead of 1080p. Anyone have issues with this on other brands of plasmas or is this specific to LG.

I'm exchanging it tomorrow for an LED set so I guess its irrelevant at this point. And that was one of the discs I was having issues with.