I'm not sure what causes this to be true but I know this is true for Dreamcast games also. You have to be very, VERY particular as to how you burn them for them to work, and burning them at a certain speed is one of those particular things.
it has to do with the disc writing process. Writing data to recordable disc media is basically a chemical reaction being caused by the writing laser as opposed to factory media which is pressed. and at slower speeds the data is being "burned in" to the media more thoroughly so when played in a system that is reading large amounts of data relatively quickly it needs to be burned in there nice and good.
this is why early CD players had a hard time reading burnt CDs and a lot of DVD players are finicky with burnt dual layer media and also why the quality of disc being used matters as well.