I would probably advise a couple of things. 1, to try a different SD card. or 2, try doing a simple format to FAT32, and run a simple GB rom. Only to see if it backs up with the basic methods without doing EXT4 partitions.
Also, after looking at your Alpha Rev info, I would also advise you flash to a different version of HBoot. You have a kind of strange one there. You might want to try one of Alpha Rev's, like the CM72 version. Could also be an issue.
And, your radio is a little outdated as well, but that shouldn't effect your backup.