scroll bar dark mode issue

[rmmaniac]

9.50 release candidate 2 flickering of the main menu in dark mode has been greatly improved,
But the scroll bar still flickers a bit.
and When scrolling to the end,bar will turn white
P.S Test in windows xp sp3

[ghisler(Author)]

The scrollbar flickering cannot be fixed, not even with the trick I use for the menu (using WM_PRINT message).