OK, who can help? G3 233 basically stock machine with 228 Meg Ram running OS 9.1. Booted up and stalled during extension load. No problem. Shift boot and do Disk First Aid - unrepairable error ! Again no problem, Tech Tool Pro (thanks Tee for bringing it back!) plus an MO drive with 8.6 on it allowed me to do repairs. Dialogue window I have never seen before. OK with that too! Now comes the interesting part. Whenever I put in certain CDs (burned copies but not all of them!) the CDs come up (very slowly) as unreadable and asks do I want to format them. Then my system does not read any other CDs unless I reboot. Reboot and it then recognizes "original" CDs. If I then put one of the unreadable ones in it is not recognized and I have to paper clip it out . If I follow it immediately with a "good" one it too is no longer recognized forcing me to paper clip it and then reboot. I ditched preference files and replace extensions that had anything to do with CDs. It looks like I can now put in the unreadable CDs, get the format dialogue and can eject it. Putting in a "good" CD now works. Here's the rub the "bad" CDs are all readable by my other systems ( a Rev A iMac and a Cube) running OS 9.1 with no problems. Have I missed an extension (Apple Audio, Apple DVD/CD and ISO 9660), forgotten a preference file or is there something else I could/should try? Users can subscribe to the List by sending an email to <muglo-request@xxxxxxxxxxxxx> with 'subscribe' in the Subject field Users can unsubscribe from the List by sending an email to <muglo-request@xxxxxxxxxxxxx> with 'unsubscribe' in the Subject field Users must send messages or replies to <muglo@xxxxxxxxxxxxx> All messages are archived so that you can view them at any time by going to <//www.freelists.org/archives/muglo> Problems concerning use of the FreeList should be sent to <paulthomas@xxxxxxx> Don't forget to periodically check our web site at: http://muglo.on.ca/