Hm. Reading the thread in more detail. In an earlier post you said that the screen was "a little smaller" then fullsize. So it's not super tiny? I can't see your monitor so I am guessing that this is the intended design. The game was made at 320 x 200, and in order to keep the proper pixel proportions it scales itself up to fill your monitor using the exact same aspect ratio. (640 x 400, 960 x 600, etc). If that doesn't slot into your monitor size precisely, black bars will be added to the edges.
Is that what is happening? The playable area is "slightly smaller" then full size? If so, that's as designed. To do otherwise would stretch out the pixels and make everything look ugly. Sorry about that!