Hi Doug,
>What I'm seeing is this: When I press the down arrow key and the lower (or upper) table has the little outline box (waiting for me to press the spacebar) it moves back ALL BY ITSELF to the starting, highlighted table/cursor.

Better call the Police! Sounds like a Ghost in the Machine. <G>
Seriously, I've NEVER seen anything like that. Unless you have a stuck key or something. Wow.