Causes of CD player skipping?

Lube those rails!

Update.
It worked!!
I took the cover off, cleaned the rails, lubed them, and the player works perfectly normal now.
Thanks to all of you for saving me some major bucks at the repair shop!
I called the local repair shop Wednesday and they told me my laser assembly was bad, and that it would cost a minimum of $200.00 for parts and labor!
Thanks again to all of you.

Hello, I have the SAME problem as you did.
Can you piont out to me where the Guide
rails are on a Sony CD changer?
Do you have a service manual?
Let me know. Thanks.

BEWARE:
CD player gears and the plastic sliders that run atop the rails are made of nylon or Delrin.
DO NOT use regular household oil, 3 in 1, WD40 or any oil with solvents on plastic gears/sliders. WD40 has paraffin in its formula and will leave a sticky deposit.

Most of those lubricants start a chemical reaction with nylon and eventually the nylon part will crack or break. It may take a couple of years but it does happen. If in doubt read the Philips CD player service manuals.

There is a grease made specially for lubricating CD/DVD/VCR nylon parts. It is available through electronics parts stores/distributors.
White lithium grease from Home Depot is OK too, it does not attack plastic parts.
It is also available from Auto Parts stores and on ebay, search for white lithium grease. Avoid the ones mixed with molybdenium, they mess up the parts.
Use sparingly, apply a very thin film with a Q-tip.
Good luck

I found the correct grease.
Search for CDM9 grease on eBay.
Good luck