Thanks for the sample, I can make the sample go wrong as well. Here is how I made it mess up.
1.) When form loads, minimise the child window onto the mdi parents dock.
2.) Restore the window to previous state by clicking on the first(two squares over each other) sizing control.
Et Volia, grid is all messed up
I have attched a zip with screen shots.
I am running .net v1.1 vs latest version with all updates.
Mark
mdiscreens_3151.zip