Can someone clarify what is meant by the Redbook standard. My understanding is that even disks over 74 minutes conform to the Redbook standard? I am getting a clicking sound coming from my Marantz CD7300. While it is not consistent and does occur on disks less than 74 minutes it seems to be more often on disks over 74 minutes. It occurs on home recorded and commercial disks and mp3 disks that the machine supports. Marantz have said that only Redbook disks are guaranteed with their models. I am having it looked at but may get in dispute with them as it is difficult to replicate (eg restarting the disks can clear the clicking noise). I have had it less than a year.