Originally posted by -megalithanod:
It was more than likely a PS7 upgrade version. They verify that you have certain files with the previous version to warrant you only spending the dough on the upgrade and not full retail.

They more than likely included the needed files for the verification check into a folder, and you directing the install to that folder trcked it into thinking that you had the previous version installed.
<font size="2" face="Verdana, Helvetica, sans-serif">Ahhh! I bet that's what it was.