If you have the 3.01 version from x series, my guess is your going to have to go back to 2.006 or earlier for the flash to work.
Obviously the update was designed to recognize a legit version to update from. if its not there it will prob just boot up as normal. I made a copy of 2.006 just before i copied over the x series flash disk. It is amazing how well that worked, don't think pioneer thought of that one. Guess even if they did how would they prevent it anyway?
Also, one would assume once someone has done the flash, a backup of the drive may be possible. Unless of course they some how made it only work on your particular unit when its activiated.
guess we will find out soon enough, i will be happy to post my flash drive once the update is done, just to see if it will work.
It sounds like from some reports it wipes out all your settings, so it might not be smart enough to check for that stuff. Since it's easy enough to go into service mode and just do a rebuild from the X series 3.x backup I will just give it a shot.