Yes, I ran blkid and the partition with that UUID exists. The software was a proprietary driver for a video capture card, but I don't know if that will help.
I think the problem is that that software modified /boot/initramfs-2.6.32-279.el6.i686.img and somehow corrupted it, but I'm not smart enough to know what that is.
I booted into another OS on this machine, and tried this:
> gzip -dc /boot/initramfs-2.6.32-279.el6.i686.img | cpio -i
gzip: /boot/initramfs-2.6.32-279.el6.i686.img: unexpected end of file
so I think this must be where the problem is. If that makes sense, how can I restore /boot/initramfs-2.6.32-279.el6.i686.img?