For anyone who has "bricked" their player. I've found a couple of things. 1) take out any memory cards. 2) plug the player into your computer. 3) Try starting it in it's OF. Keep doing this repeatedly - holding down the home and power buttons for 10-15 seconds at a time, take a break, and keep doing it. The player will eventually start up again in OF, then you can unplug and start in rockbox just fine.
Unfortunately, I've "unrockboxed" my player
I started having this problem every single time my player was turned off for more than an hour or so, and I just can't bring my computer with me everywhere to get it started again. I'll patiently wait for some more stability this time. Thanks to everyone for their hard work on getting this going though!
The nice thing is that, as long as you FOLLOW DIRECTIONS, I think it's almost impossible to brick the player...just takes some extra effort sometimes to get it going.