When using the Graphics2D.drawRenderedImage() call, all is well when the
clipping region encompasses the entire canvas. However, when this is not the
case, the image is drawn with its upper-left corner starting at the bounds
of the clipping region. This results in incorrect repaints.

A test program contrasting the behavior of drawRenderedImage when its argument
is a BufferedImage (yielding correct behavior) and when it is not is provided.
To compile:

javac -classpath jai.jar:. Test.java

To run:

java -classpath jai.jar:. Test

Drag an obscuring window over the display; the left side will refresh incorrectly while the right side will correctly repair itself.