strange behavior in runtime

I have a solution that has 5 open windows stacked one on another so that only 1 is visible at a time. If run when the monitor display is larger than the window, I use move/resize to position the windows in the center of the screen. The move/resize statements are identical for each window.

In the case where the display is larger than the window, everything works fine until I build the runtime. Then the first opened window does not position to the center of the screen. The other 4 do position properly. And when I 'grab' the mis-placed window to drag it into position, it vanishes (not visible in task bar). Similarly when I grab any of the other windows, they vanish. They don't vanish when not in runtime!

I'm using SecureFM to restrict the user's ability to maximize/minimize/close the files other than through scripts and have disabled virtually all menus. After the window 'vanishes', it's still listed in the 'Window' menu, but since I have disabled the 'Window' menu, the window can't be recalled from wherever it went.

What's going on??