I downloaded the netinstall .ISO for Debian Etch. My computer simply refuses to boot it. Everything in my bios is correct - I tested other distros and they booted fine. I even reburned it, burned a different one with the same method (which booted), etc.

I would bet that the iso that you downloaded is corrupt, especially if you can boot other linux distros on the same computer. You've eliminated the possibility that it is a hardware, BIOS issue. For the fun of it you could try booting the netinstalliso on a different computer, see if it boots. If it does not then you know it is faulty.
I would re-download the iso once you've determined that the CD will not boot.

I had the same problem with the netinstall version. The businesscard image worked for me.

Interesting. I've used the netinstalliso for the last three versions of Debian Etch. No problems. I'd be willing to bet something else is going on here.

"Interesting. I've used the netinstalliso for the last three versions of Debian Etch. No problems. I'd be willing to bet something else is going on here."

I don't know what to make of it. I just took a look at my downloads directory and the one I downloaded 12/9 was still there. The thing is that it's WAY too tiny - only 856064 bytes. The stranger thing is that I can open it with "-o loop" and it shows a zero length file called "hdc". Would a partial .iso file even open? The one I downloaded just now looks to be the proper length and its contents look a lot more reasonable. Maybe they had a bad one there the night I downloaded? I remember downloading and burning several times before trying the businesscard version. I was almost out of blank CDs and was getting most annoyed.

Yes. Agreed. I'd say 85 MB is way too small for a netinstalliso. That sounds like a partial download or a corrupted download, methinks:-)
I'll be downloading Etch when it goes gold code. I'm very impressed with Etch release candidate 1, no glitches yet:-)
Yep, been there, done that, I hate running out of CDs when things go bad:-)