I have an in-place animation of fruit machine reels. These are implemented by 3 ImageViews with a Y transition, clipped by a Rectangle.

The animation runs at a good frame rate with fullspeed=true (around ~530 fps). However, when I maximize the application window, the frame rate drops to ~150 fps, even though the effective area of animation hasn't changed. This seems to suggest to me that the entire window is repainted every time, although prism.showdirty=true shows that the dirty regions are calculated properly. This behaviour happens both using the d3d renderer as well as using the j2d renderer.

This seems like a bug to me, although to be honest I'm not quite sure what the reason is. On a side note, with a maximized window I'm seeing choppy animation on my screen, much worse than should be possible with the reported FPS (I should not be able to tell the difference between 500 and 150 fps, right?). This could all be an artifact of my GPU and/or driver but then why does it also happen with the software renderer?

I've attached a NetBeans project (with a runnable .jar inside) that exhibits the problem.