WinLAF:JScrollBar differs on mouse over while compare with native scrollbar in vista.

Bug Info:
=========
Mouse over on either scroll channel and scroll box,the scroll channel should change to blue color and scroll arrows(up/down) should get highlighted.

I excpected the above described behavior based on native scrollbar in vista.But the scroll arrows are not getting highlighted on mouse over in JScrollBar.

I used the default windows vista theme.