CoreAnimation jerky with large window

Question

I have a very simple CA demo. It creates a layer with content from an image file, and displays that image. When you click in the window, it uses implicit animation to smoothly move the image to the mouse point. This works fine, runs with perfect smoothness. But, as the window gets larger, the smoothness gets less. It's acceptable below about 75% of the screen size. With a maximized window, or in fullscreen mode, it is very rough and jerky.

I'm running OSX 10.5.7 on an intel Mac Mini. It has an intel GMA950 GPU. My screen is 1920 x 1200.

I do not have a drawRect method at all. Everything happens by setting the position property of the CALayer, using implicit animation.

Am I right to suspect that the hardware is at fault here?

Neil Baylis