Hi, First time poster here but you might of seen me around ASSEMbler and TiZ selling the Phantom (Mine and Bad_Ad84's chip).
I agree that APE wouldn't of sold it to you unless it was working correctly. I wouldn't mess with the pot, it's most likely your burner and/or CD-R's you're using. What CD-R brand you using? Generic, Taiyo Yuden?
He said above they were real games which I am assuming means they are not cd-r. Also he said it plays music cds fine, so I'm not sure what could be the issue.