I posted this in the another thread, but to get the game to scale properly in Windows 7 using the standard wrapper do this:
There should be a file called glide_wrapper.zbag.ini somewhere in your appdata or Application Data folders (depending on which OS you're using).
Edit that and change the high_res=0 option to high_res=1
Then the game's 3D will run in a higher resolution, and it'll scale properly using Nvidia's fixed-aspect ration scaling if you have an nVidia card. There will be a small border around the image, but it's almost full screen on my 22" monitor.