I posted this question in the general and didn't get a answer about the numbers on the bottom of the unit so here it is again. I bought a 730 on ebay that said "New" but when I received it, the book that was sealed said 720 on the top of the pages. I looked at the bottom of the unit and at the end of the serial number it has GO520 did I get taken or does some of you guys out there have that on yours. I haven't been home to put the disc in the computer or turn the unit on yet. I need to know before I get a hold of the seller to complain. Thanks in advance, Joe