You can also try this:
1. go here
2. in the search box at the top, search for bqdaiad
3. click on the Vostro 1000 link
4. click buy now
5. click add to cart
6. when in cart, enter coupon code RH23N?MWL3KF1C
7. price should be $399
the only issue is doing it that way gives you the slightly lesser AMD Sempron processor instead of the Athlon. once they update the special e-value code in the original link, it should have the Athlon, but if you just want a $399 laptop, the steps above should work.
Or if you don't want to wait while still taking advantage of the $260 coupon (RH23N?MWL3KF1C), I found out that if you follow Brad's steps above you can customize the system configuration by clicking on the "Adjust System" link when the laptop is in your cart.
To upgrade to the Athlon TK-53 processors, it's an extra $50. And what I like about this is that you can customize other components while still getting the $260 off.
As of this post, it seems the "bqdaiad" is for a Vostro 1000 with XP only as Vista is not offered as an alternate OS. That's the only difference I've seen.