This is pretty simple.  Just set handled = true on HandledMouseEventArgs:

// prevents the scrolling through of the items when the UltraCombo is closed.
UltraCombo combo = sender as UltraCombo;
if (combo != null &&
    !this.ultraCombo1.IsDroppedDown)
    ((HandledMouseEventArgs)e).Handled = true;

Or

// prevents the scrolling of the underlying drop-down grid
UltraCombo combo…

I’m looking forward to meeting up with a bunch of customers in Texas this week.  Here’s my schedule:

• Monday – Tuesday: Dallas
• Tuesday – Wednesday: Austin
• Wednesday – Monday: Houston

If anyone is around feel free to send me a message and if I have time perhaps we can get together for an informal what’s going on in NetAdvantage session.