Maybe it'll just go away, a friend gave me a saturn he hadn't used in like 5 years, and he said that it had the same problem you are describing, took it home and worked perfectly, still does to this day
hey, i have the same problems with a few saturns as well. keep the game and the saturn running for a while [i leave mine on for a 1/2hour or more] and then it should work fine.
i dont know why that happens, but it doesnt mean it aint functional.