clearRect() should be drawn with background color.
As delegate's background color is set to 'TRANSPARENT' when delegate is created,
the patch would do no harm for normal case.
Index: src/com/jmex/awt/swingui/ImageGraphicsBaseImpl.java
===================================================================
--- src/com/jmex/awt/swingui/ImageGraphicsBaseImpl.java (revision 4390)
+++ src/com/jmex/awt/swingui/ImageGraphicsBaseImpl.java (working copy)
@@ -321,7 +321,7 @@
//fix for bug in JDK1.4:
Color color = delegate.getColor();
- delegate.setColor( TRANSPARENT );
+ delegate.setColor( delegate.getBackground() );
Composite composite = delegate.getComposite();
delegate.setComposite( AlphaComposite.Clear );
delegate.fillRect( x, y, width, height );