Any customer who has had a PCM serial number incorrectly deleted by EFILive, will need to use the newest version of EFILive available here:
http://www.efilive.com/download.aspx#download1
That new version will program a pseudo random serial number into the PCM during a full-flash if a blank serial number is detected. Once that is done the PCM can be licensed and reflashed normally by EFILive.
Obviously that may "waste" a previously used license for that PCM. If that is the case please contact me directly at paul@efilive.com and EFILive will provide a replacement license.
Regards
Paul