i tried to backup battlefield 2 and i ftp'd the info to my comp from the dvd drivr and then i made the info an iso using qwix and the i tried to burn it using nero at 2x onto a dvd-r memorex. it says invalid media type when i try to boot it.
one thing it might be are the DVD's Memorex just plain suck. Try a different brand and see if it works Philips,TDK,Taiyo Yuden,Ritek,Verbatim DVD-R 8X speed burn at 4X
i use memorex for all of my dvd's like movies that stuff works fine but none the less i will try other media
they may work fine for movies, but movies are not nearly as picky as games when it comes to media. I tried a few Memorex when i first started backing up games and didn't know anything. They never worked. I always got the "not a valid PS2 disc" or "please insert a valid PS2 disc" type message