Scroll buttons in JTabbedPane with SCROLL_TAB_LAYOUT policy are behaving
inconsistently with the attached code on both Solaris & Windows platforms.

To reproduce the above problem:

1. Compile & Execute the attached code.
2. Scroll towards right by pressing RIGHT scroll button till it gets disabled.
3. Then again start scrolling towards left. It won't scroll.

This is happening only with the launched JFrame size. If you decrease the
size of the JFrame a bit, before executing the test instructions, and then
test it, it is working fine.

I traced back with the old builds. It is working fine with builds before b52.