Ok, I've run into an apparent problem with grid repainting. Under certain conditions, if I show a form on top of a grid and then remove it, the underlying grid doesn't always repaint itself. I can "repair" the damage with []WI 'Paint' or user interactions, but not with []WI 'xRedraw'. This problem has been duplicated on Windows 98 and Windows XP systems, APL versions 4.0, 5.2 and 6.2, and grid versions 5.0.20.0 and 6.2.0.2. I've attached a demonstration workspace for you to try. See the function comments for additional details.
Attached file: GRIDBUG2.w3