If you look at the stock heatsink you will see the gray pad like area. That is the stock thermalpaste.
If you got the OEM CPU without a fan, or you want better thermalpaste go to Radioshack and get some arctic silver 5.
That mark can be from the factory when they tested it.
Thanks, that resolved a lot! I never thought to check the bottom of the heatsink, lol. I actually did pick up Antec Formula 5, which I heard is almost as good as Arctic silver 5. I guess the only thing now is to download the latest BIOS drivers, and see if it works, if it doesn't, then I could just return it. Thanks a lot for your help!