Update released.
the 32-bit thumb scrolling support works now properly in each "scenario" in the ListBoxW control.
Means vertical scolling is always 32-bit.
Horizontal scrolling is only 32-bit when also the MultiColumn property is set to True.
Else it remains 16-bit, which is the case for 'HorizontalExtent' scrolling. And that should certainly be sufficient.

Sorry for the confusion..
I also think it gets time to bring out the next OCX release.
But as the forum rules are restricted about closed binaries I am thinking of publishing the source code along the binary.
This way I could upload everything in "UtilityBank - Components" and make a link from here to there.
What you guys think?