I'm trying to customize a scroll bar's appearance by changing its stylesheet and I've been able to achieve nearly everything I want to do except for changing the 'handle' sub-control. If I do anything with the handle, something ends up working incorrectly elsewhere in the scroll bar. For example, if I simply add this to the bottom of my stylesheet:
Qt Code: 
  1. QScrollBar::handle {
  2.    background: rgb(255,255,255);
  3. }
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the resulting scroll bar has a white handle but it allows the handle to be dragged over the full extent of the scroll bar control, including over the add-line and sub-line controls! Other changes cause other strange behaviors, such as the add-line and sub-line controls being fully obscured by the add-page and sub-page areas, etc.

Here is my stylesheet in its current state; it works exactly as I want except for the handle styling:
Qt Code: 
  1. QScrollBar:vertical {
  2. 	background: rgb(64, 64, 64);
  3. 	min-height: 50px;
  4. 	width: 50px;
  5. }
  6.  
  7.  
  8. QScrollBar::sub-line {
  9. 	border: 1px solid white;
  10. 	image: url(:/Common/arrow_triangle_bright_up.png);
  11. }
  12. QScrollBar::sub-line:pressed {
  13. 	image: url(:/Common/arrow_triangle_black_up.png);
  14. 	background: rgb(255,255,255);
  15. }
  16.  
  17. QScrollBar::add-line {
  18. 	border: 1px solid white;
  19. 	image: url(:/Common/arrow_triangle_bright_down.png);
  20. }
  21.  
  22. QScrollBar::add-line:pressed {
  23. 	image: url(:/Common/arrow_triangle_black_down.png);
  24. 	background: rgb(255,255,255);
  25. }
  26.  
  27. QScrollBar::add-page:enabled, QScrollBar::sub-page:enabled  {
  28.     background: none;
  29. }
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Is there something wrong with my stylesheet and it just happens to work if I don't mess with handle styles?

I'm doing this in Qt 4.5.0 (yeah, I know this is a fairly old version) under Win7/MSVC2005 (also kind of long in the tooth).
Has anyone encountered this problem? If so, how did you resolve it?

Thanks!