I have two users so far with issues.
AlienwareX51_Josh upgraded from A03 directly to A13 went in order loading A12, then A13.
seahster upgraded from A06 directly to A13.
Have any X51-R1 users loaded A13 successfully? If yes, did you load the Bios in order (A01, A02, A03, A06, A07, A11, A12, A13) ? Or did you skip some and go directly to A13?