Mouse wheel scrolling does not work at all for me - after inheriting from sourcegrid and stepping into the event handler, I noticed that in CustomScrollControl.CustomScrollWheel there's a threshold of 120 for the mouse delta - but my event only ever has
a delta of 30.
I think that you should accumulate the delta instead of just discarding values you consider to small.
In my inherited class, this override fixes the problem for me:
protected override void OnMouseWheel(System.Windows.Forms.MouseEventArgs e)
mAccumulatedDelta += e.Delta;
if (Math.Abs(mAccumulatedDelta) >= 120)
base.OnMouseWheel(new System.Windows.Forms.MouseEventArgs(e.Button, e.Clicks, e.X, e.Y, mAccumulatedDelta));
mAccumulatedDelta = 0;