Reinstalling my driver to 11.6 worked like a charm; the miner now recognizes "ATI RV770" so I think I'm good.

EDIT: Okay, new problem. I ran the miner with -w128 as the only flag; it then used all of my GPU until it got to 118 C and crashed my computer. Now, every time I attempt to start mining, poclbm.exe crashes.

No pain, no gain, I suppose.

Hi, all. I was originally hoping to post this in http://forum.bitcoin.org/index.php?topic=3878.0 but the newbie restriction is in place so I'm hoping I'll still get some help if I post it here.

My friend and I are both attempting to start mining via the GUI miner linked, but we can only use our CPU's--neither his Radeon 4850 nor my Radeon 4870 appear on the miner's drop-down list for OpenCL-compatible devices.

I've been doing some research this morning on OpenCL and ATI cards; apparently, the Radeon 4xxx series only has "beta-level" support for OpenCL, according to this list of compatible systems, etc. I'd think that beta-level support would be sufficient to mine, but I've downloaded and installed the 64-bit Windows 7 AMD APP (AKA ATI Stream) multiple times, to no avail--the mining application still fails to recognize the 4870, as does this GPU Caps viewer someone recommended in an old post I found.

Bitcoins in general seem like a fun prospect and, hopefully, a lucrative one, but I think I've exhausted all of my options. So, wise bitcoin sages: Are my friend and I SOL? Or are we still missing some vital driver or program?

Thanks in advance for any help you guys can give.