So I tried using the flasher in OS X instead, and it would actually charge the device!

So for anybody else having this problem, if you're using Win7 64bit, this might be the problem. Try in a different system. The flasher works the exact same way in OS X. There is a guide here: http://www.allboutn9.info/2012/03/fl...n-mac-osx.html

Now I can flash the phone, but it will boot to a yellow triangle with the "device malfunctioning" message, but at least I'm not stuck anymore.