Hey guys, I had a little adventure getting this to work right and thought I'd share in case anyone else has the same issues I did.
I had the "attempt to boot into recovery, get a flash of polyhedron Android and then BOOM, dead Android on-screen" issue.
I tried Theonew's suggestion from post #25 but that didn't work.
I tried cheeb's suggestion from post #26 with no better result.
I began to think that perhaps I wasn't really flashing the recovery.img like I thought I was, so I combined these steps:
From Theonew's steps, I did this:
adb devices adb reboot bootloader fastboot erase recovery fastboot reboot
...leaving out the flashing recovery.img step.
I then followed mapaz04's instructions for flashing from within Android from post #28.
After that, I installed Quickboot from the market, selected reboot into recovery and now I'm backing up with CWM as I type this...and just checked it completed successfully.
THANK YOU to everyone who has contributed in this thread -- for me, at least, it took something from each of you to make it work. Thanks for all your hard work and for sharing your knowledge.
so i did that. recoverry worked the first tuime. i got everything backed up. i rebooted back to android but when i tried to boot into recovery the second time, it would go to stock recovery and give me an exclamation point