I've modified one of my forms to allow drag/drop positioning of text boxes/labels. I'm using the manual drag/drop methods.

This all works fine, except when dragging anything outside of a 640 x 480 area, the grey outline disappears - the object is dragged/dropped correctly, it's just not obvious where its going to land. If the object starts outside the region, it's not obvious that it's being dragged.

I can't find which properties of the main form (I assume that's where I should be looking) I should modify. Can anyone help ?