Welcome to the Forums,
bronden
To start out with, realize that there are three variants of the AthlonXP 2000+: the original Palomino, the Thoroughbred, and now the Thornton. So you can see this is going to get complicated fast Boards may support none, one, two, or all three variants of 2000+.
Looking at Asus'
CPU-support thingie, it appears that the board only supports the old Palomino version of the AthlonXP 2000+, probably due to voltage-regulator limitations (the newer cores use lower voltages). To determine if you have a Palomino (assuming you now have a 2000+ that you want to try), here is a comparison of the Palomino compared to the Thoroughbred:
link
The key thing to look at is the size and shape of the CPU core in the middle there. As you can see, the Palomino's core is nearly square while the Thoroughbred is rather rectangular. The Thornton is even more rectangular than the Thoroughbred, and would look just like the Barton you can see
here (a Thornton is a Barton with half its L2 cache switched off, so their core shape is the same).
Hope that helps you out... if you want to get a Palomino at this point, the For Sale & Trade section of the Forums could help you snag one