It happened to me several times with FW10 to sound like an "ant fart". Uploaded with Fractal Bot, used System-Clean.syx, did the unit reset thing, uploaded FW10 presets. Nothing helped but a reupload of FW10. Used MacBook Pro with OsX 10.8.3 over USB. I think I switched between FW9 and FW10 around 50 times. The need to reupload FW10 happened about 4-5 times. Also, several times, after Fractal-Bot finished the FW10 upload, told me I have to repeat the procedure, on the Axe's screen there was the message that usually comes up when you manually enter into FW upgrade mode (of course I didn't do that).
These thing never happened to me on any FW upgrade (Ultra FW5 up to FW11 and AxeII FW5 up to FW9.02).
P.S.: No Axe-Edit involved