Thanks for the thorough explanation.

[quote user="Mike Saltzman"]In Windows 10, that means that by default the controls will only scroll when the mouse pointer is over the control.[/quote]

That makes sense. However, the drop-down grid is part of the UltraCombo control. Therefore, hovering over it should still make it to scroll, as opposed to having to only hover over the textbox-like portion.

We're using 15.1.20151.2132, which we thought was the latest. (We're taking this over from the programmer who usually maintained it.) You're saying the newer version always works, regardless of the Windows 10 setting I mentioned in my 2nd post?

BTW, in Windows 10, if you turn off the "Scroll inactive windows when I hover over them" feature, it works fine. However, we don't want to have to tell all our users to turn off a Windows option, just so they can easily scroll their drop down lists that some of them want to keep on. Especially as it appears that setting should not interfere with how this control has always worked in the past.