Playing video through a Plasma TV

I have a fifth generation Ipod and the Apple dock with AV connection. I am able to watch through the television for our two LCD televisions just fine, and have used the Ipod and dock when traveling with hotel TVs, but it doesn't work properly through our two Panasonic plasma TVs. I get the video on the TV screen, but it's poor quality and rolling. I heard, but not through an authoritative source, that the video ipod just won't work with plasma TVs. True? Or is there a trick to hooking it up that I haven't figured out? We have tried every combination we can think of and have adjusted the video input settings on the TVs, to no avail.