marks [hopefully] one of the most egregious issues with Swing desktop apps. If your box was busy enough, you could stare at a grey rectangle for several seconds after someone had tabbed away from your app for a few minutes and then decided to come back. It was really annoying -- at least I hope this is past tense.

... when a Swing based app is exposed after being hidden by another application there is a noticeable delay between when the background of the window is erased and when the actual contents are painted. We've come to call this the 'gray rect' problem. I'm happy to report that with the promotion of mustang build 32 this bug (4967886) has been fixed! Download it now and give us feedback!