AWT Scrollbar shows a blinking shade on top of the knob when it gains focus.
But its noted that the shade is not lost, even after the scrollbar lost its focus. Hence more than 1 scrollbar is seen as having shading (indicating it has focus). Attached here with is the screen shot and sample code.

Bug can be reproduced in 1.4.1, 1.4.2, 1.5.0.

The visual indication is misleading for the user and the bug has to be fixed.