I succeeded in updating the BIOS to version 1104 and still no luck, even after I reinstalled Snow Leopard for the 3rd time. Some thoughts:

-I am using a 10.6.3 DVD. Could this be the problem? I'm using the newest NBI available from Meklort's website (http://www.meklort.com/?p=262).
-The wifi did work for a very brief time - the very first time I ever booted from the SL USB drive and the 1000HE's HDD hadn't yet been partitioned. At that time, I still had the option of turning off Boot Booster, which I understand is not related to the BIOS as much as it's related to the recovery partition that comes on the 1000HE along with Windows XP. After I partitioned the entire drive and installed SL (and subsequently lost wifi), the Boot Booster option went away; all I have now is Quick Boot and Quiet Boot. These are both disabled, btw.
-I took the battery out and the wireless module sticker says: "AW-NE771" which, as far as I've read, is the supported card for this computer. Like I said before, under About This Mac... the installed wireless card is Atheros 9280. I'm really at my wit's end about this.

In the meantime, I'm going to make an Ubuntu live drive and boot from that to see if the wifi card works with Ubuntu (it did when I booted into Ubuntu with my intact Windows XP install). This could possibly indicate whether my particular wifi functionality is tied to that recovery partition from the original install. Is there anyone out there with similar problems? Any input?

Thanks