I had this problem and used nbdew002's update method and my unit works again. figured pioneer was just reflashing it anyways.
I had to download unmodded update from pioneer cause the update did not like my data.zip.
http://avic411.com/forum/viewtopic.php?t=20119
thanks for the info on all this nbdew. I'll be damned if pioneer is gonna take my unit for 10days (probly 20 cause im in alaska) after all the mods to my commander dash to get that thing to fit.
edit* if you have a 2gig SD card all the files will fit on there