So, I went into Print Management, and created a new form called Video Game, with the same dimensions as legal paper, and set the Margins to 0.5 for each. Saved it, then opened Paint.
I select Video Game, which is all set for me, and that right Margin goes back to 3.478. *SIGH*
So, I've decided that it has to be the printer driver that is causing this problem. It HAS to be. My only problem is, locating this driver, and maybe editing, or replacing it. But to replace it, would have to find the correct replacement.
Any ideas?