Help: can't read internal CD drive

[Eytan Bercovitch]

Hi,

I've noticed that my internal CD drive has stopped
reading/recognizing CD disks when they are put in the
internal drive. If I put a disk in, nothing shows. 
The drive does open and close as usual when I push the
manual control on it.

I am running MacOSX 10.2.8.  I am running on a 400mz
G4 of the Yikes (PCI) model with 728 mg RAM.

When I restart in OS 9.2 (which is also on my hard
disk) the internal CD works fine, and reads disks
normally. 

So this is not a hardware fault, as far as I know.

I have already run Norton Systemworks 3 and Disk
Utility, and the problem remains.

My question is: Does anyone have any suggestion as to 
1. Can you think of a way figuring this out and fixing
it?
2. If that doesn't work, what else should I do?
(please don't tell me do a clean reinstall of OX10.2
except as a last resort).

Thanks!

Eytan