Paul Clarke made an interesting remark about the general "your disc is dirty" message your CD-i player might give when actually the timekeeper is dead or the disc has stopped spinning: "Could be something to do with the disc but also please note that "your disc is dirty" was the fallback error message for any error condition on a production CD-i player as it forces user to take out disc and reset player. This maybe why it happens when real-time clock batteries fail... may have led to a divide by zero error etc"
[Thanks, Paul]
