The honeymoon with the iMac seems to be over...

Got the 800 Mhz 15" iMac flatscreen, and the SuperDrive is giving me

For the last 3 months, I was having a hard time mounting CDs. I used
these CDs frequently enough so that I tried making disk images,
sacrificing hard disk space for reliability. I can rarely get an image
to save correctly. Mostly I get an error message somewhere in the
imaging process, and not always in the same spot.

I've got a stack of old CDs burned on a 9600 a few years ago, and it's a
hit-or-miss process as to which ones will read in the iMac. Some will,
some won't, and some seem to read if the moon is in the right phase (OK,
sarcasm here)

CD's burned on a PC will not always mount. Seems to depend on the type
of CD-R used.

Sony & Verbatim CD's burned by a friend on an eMac will not mount. The
drive just grinds away for a minute or so, then ejects disk.

The final straw was burning 2 CDs this afternoon on the iMac, and not
being able to mount them after ejecting and reinserting. Same deal...
drive just grinds for a bit, then ejects disk. Discs show as
uninitialized on a 7200/90. I'm using Memorex & Sony CD-Rs, not the
bulk cheapo discs.

I can burn & mount DVD's just fine. It seems to read DVD's without any

I really can't afford to buy an external DVD-R drive right now, but I
need CD's to load.

Does anyone have ideas? I can't really tear down the iMac and pull the
SuperDrive, and it's about 9 months out of warranty. (bought
secondhand, so no AppleCare) I've used a can of air to try and blow
dust from the drive, but that had no appreciable effect.