A lot of games mess with settings, and when the code abends or somebody pushes the windows key or alt-tab (for example), the user is sometimes left with a wierd-looking screen.

You really better be sure that, with the exception of errors you can't handle, you cannot get out of the app without at least trying to reset the resolution. This is a challenge. Which is why most shops don't allow that kind of thing for production code.

If this isn't a game, why mess with resolution? Are you using a 6 point font or something...