It certainly sounds like the CD. I would suspect a high speed burn had been done, assuming that you verified that the download was good with the md5 check. A disc burnt at a slow speed from a confirmed good download would likely resolve your issues. If you have 1 gig of RAM available you might also try the toram cheat code to get everything loaded into ram and then your CD can stop spinning all it wants and there will be no problem, but if it's a bad burn then toram may not help.