So I installed the GM just fine on my Air but my imac is giving me some issues. It's an 09 i7. I don't have the orig disks that came with the mac. I do however have my flash drive from my air and 10.5. When I boot to the USB or the CD with 10.5 I get an error after the language select saying that osx can't be installed on this machine please do a restore with time machine. Now I said yes so I could get to the disk utility. I erased my drive and I still get that message. How can I solve this issue to install the GM on a fresh drive?