Jerry,
I just tried it out at 800x600 here and you are correct - it is just a little bit oversize in the vertical direction. I will work to correct it on the next version.
As a workaround, I noticed that if you grab the window bar at the top and move it up just a bit you can access the buttons at the bottom to press OK or Cancel. Its not perfect, but you should be able to work with it until I can make the fix.
Thanks,
Brad