GWR

I do all of my MD listening in the car, on a 5-year-old Kenwood single-disc MD/radio head unit. I compile my discs using a 5-year-old Kenwood standalone recorder. I'm finding that more and more of my discs are starting to "stick" - they'll get to a certain part of a song and then the audio will stop dead. You can hear the mechanism inside the player trying to read the disc, and you might hear the occasional short burst of audio before it sticks again, but normally all I can do is just skip to the next track. Can anyone point me in the direction of a cause? Is it likely to be a problem with the discs (I don't store them in their slipcases), or the heads in the player? FWIW, it only seems to happen on discs that I have been playing regularly for a few months; I never have any problems at all with brand new discs.