How to link Screen Resolution to Profiles??

I'm running Win XP Pro on a homebuilt system with an Athlon 64 X2 on an ASUS mobo, and an ATI All-In-Wonder 2006 Edition video card feeding a ViewSonic flatscreen at 1680 x 1050 pixel resolution in 32-bit color. I have set up 2 profiles - mine, and another for my grandson who likes to play on-line video games that prefer lower resolution. So to play, he signs into his profile and changes resolution down. When I go into my profile, it's in the lower resolution and my layout is all changed. I have to change it all back after resetting to 1680 x 1050.

I know there should be a way to specify the resolution for each user profile separately and make the settings stick, but I can't find it. Is it in Windows, or is it an ATI setting?