So, I have a back up of Auto Modellista (PAL), for the PS2. Of course, it fits on a CD-R, which is exactly what I threw it on. It's been patched, and written at 8x, Disc-at-once. The burning to media was fine, but for some reason, this game won't load with the Swap Magic CD. I selected PAL from the SM 3.6 screen, and it gave me that "Not a valid PS2 game" error. I even tried the normal, and NTSC mode to see what happens, but to no prevail. I thought that maybe the Zoneloader CD would work. PAL, NTSC, and normal mode tried with Zoneloader, and I got a "fatal error code - 7" message. Could anyone help me with this? It's bothering me like crazy. =/.
It may fit on CD, but it could of been a DVD image, with DVD media checks. Did you check this out before just 'throwing it onto a CD'?
That would explain why it won't work.
Open the original image in IsoBuster. If it's just got a red iso tab, then it should just be a CD image. But if it has BOTH a red iso & a green UDF tab, then it should be burnt to DVD, or you'll need to convert the game to run on CD & change the media checks from DVD to CD.