@doonit: Really happy to hear that you're out of the woods. Now I'm curious if this the same reason that everyone else here are unable to reflash. You should spread the word doonit!
It's been said once somewhere that this COULD be the reason, but now we know, don't we? The flasher3-5 wiki page should be updated to say that good battery level is absolutely crucial to be able to do that flashing method.