It's probably based on an Atheros wireless chip. For Mac OS X, you want one based on a Broadcom chip. (The exact opposite advice of what'd you get if you were going to run Linux.
I'm kind of not surprised that you can only run SL. Is that generation of Atom even 64-bit compatible? (If not, then it rules out Lion.) And I suspect that you have something like GMA945 or GMA950 graphics which aren't supported after Lion, anyway.
If you can't tell... I did once try to run SL on an AspireOne D250 (a pink one at that), but got fed up with the compromises.