As discussed here, when resizing a Swing application in Vista (and Windows 7, which is what I\'m using) you get a black background in the right/bottom corner while Swing\'s
I also noticed this. For me this issue was solved with changing layout manager (I've used Free Form Layout before) and it worked pretty well (system color painting).
But eventually I switched back to FFL. Also some well known apps face this problem (f.e. SKYPE), but I actually don't mind it ...