vers:3.0.5902.39628
works fine for me.
My apologies. It is working but I wouldn't say it was fine.
The border colour is being dimmed when applied to the narrow scrollbar slider.
Using 255,0,0 for a default border shows as 238,165,163 when narrow.
This only further exacerbates the need to barstardise the default colours to get a good contrast for narrow scrollbars.
I think I will remove the ScrollBar.Lowlight elements from my skins and not bother with it in the present form.

It's not very important, but I noticed that if a gradient is set for the scrollbar, that gradient is gone when an adjustment to the width is made.
I have changed it so it doesnt do that if the scrollbars are narrowed by the skin config. The gradient still gets removed when the user chooses narrow scrollbars.
The gradient is back for the slider, but not for the background.