Can't insert DVD or CD disc into superdrive

First verify there isn't anything stuck by using this eject sequence:

http://docs.info.apple.com/article.html?artnum=106752

If that doesn't work, you may have to take your machine in to service. External Firewire drives by http://www.macsales.com/ are just as functional. You may find others compatible with http://www.patchburn.de/ or on http://www.xlr8yourmac.com/ which can help as well, especially if your machine is out of warranty.

Since no one followed up on this, and I couldn't find a solution for this problem to save my life, I figured I'd post my solution to make sure no one has this issue again.

If your powerbook has the "lock" pin in the way, put the machine to sleep by closing the lid. Allow the machine several seconds to completely become suspended (HDD stops spinning).

Lift the lid to wake the Powerbook, then IMMEDIATELY place a CD/DVD within the drive with about 50% force. The "lock" pin will disengage, and return the drive to normal operation.

I beat my head against the wall for days trying to figure this out, so I hope this helps anyone else that stumbles upon it.

I have the same problem with my superdrive, none of the above ideas worked for me.

I did this and it worked. However, I have to have the disk half-way inserted, and while I lifted the lid, I pushed my DVD in and it worked.

Thanks