There are a few problems with the painting of JProgressBars in the Windows L&F.

1) As the progress bar increases in value, the segments and chunks are not being painted as a whole. I believe they should be painted one chunk at a time.
2) The chunks seem to change in size and shift as the progress bar increases in value. This looks really awkward.

Apparently, the second problem may not be reproducible on Windows 2000.