DVD is jittery like a claymation movie

Check Activity monitor to make sure that no processes or daemons are using a lot of your CPU cycles. Even if all your applications in the dock are closed, you might still have stuff running in the background.

 

Well, if when you're not doing anything with no applications open your CPU is more than 25% consistently taxed, you've got something using too much. But for DVD player to studder like you described, you'd have to be close to maxing out your CPU when not playing the DVD.

 

Sounds to me like DVD Player's new de-interlace engine is getting messed up (detecting cadence incorrectly, bad cadence on the tape) or something to that effect. That seems more likely than the CPU being too overstressed to do MPEG-2 decoding (which in this day and age is pretty low in terms of demands).

EDIT: Or maybe you're experiencing screen refresh tearing?

 

That makes it sound like what killmoms is describing with the deinterlacing. You could try turning off the deinterlacing and see if it plays any smoother.

 

It's a menu item in DVD player. I'm not at my mac, so I'm not 100% but I think it's under the view menu. You probably don't want to have it off for other DVDs that work fine with it on since you probably don't want to see the little horizontal lines from it.

 

What resolution is the screen? Does it play fine if it is just in a small window? I have observed that GMA integrated graphics can become crappy once the resolution surpasses a certain point.

And have you installed the Leopard Graphics Update after you installed 10.5.2?