I don't know how cursor draws got much more expensive, but in previous VMs, I'd see a small CPU increase (%11 CPU on Linux/X11) if I moved the mouse quickly back and forth on the background form. As of commit 4d3f02655d, I see the CPU spike to 80% for the same task. This is using a Squeak5.1 image, and the machine is a not too old i5 desktop. Something seems to have taken an unreasonable hit. What gives?