Unsolvable kernel panic error? At wits' end...

I was playing World of Warcraft on my iMac with os x 10.5, everything seeming to run normally, when all of a sudden the screen started flashing on and off repeatedly. The computer then cut off, and then I started it back up, I received the error "You need to restart your computer, hold the power button..." on a grey background with a power symbol in the background.

A bit of FAQ-hunting told me that this error message was indicative of a "kernel panic" issue. I've read a lot of troubleshooting strategies for fixing this error, but none of them seem to help at all.

Holding command-option-P-R at startup does make the startup chime repeat, but doesn't seem to do anything else. When I finally let the computer boot, it returns the same "You need to restart your computer" error.

I've tried re-starting into single-user mode. I'm able to do so and run /sbin/fsck -f, and it runs through a bunch of checks. The first time it said it had repaired something, subsequent scans said everything was fine. When I typed "exit", the computer ran a bunch of checks and then froze completely. I tried it again and typed "reboot" instead and it rebooted straight back into the "you need to restart your computer..." error.

Command-option-o-f at startup just doesn't do anything. The computer boots back up into the error.

I have inserted the OS X Installation CD 1 that came with my iMac. I'm able to get into the hardware test by holding D as the computer boots, but it finds no errors.

Holding C as the computer boots doesn't do anything.

Holding shift as the computer boots takes me to the screen where I can select either the Mac HD or the Mac OS X Installation CD 1. I try selecting the CD and it boots back into the error.


Does anyone know what all this could mean? Is there anything else I can try, or do I pretty much need to bring the iMac to an Apple technician?

This is a major bummer. I've never had problems with this computer and I rely on it a lot.

Considering everything that you have done, and the results you have received from the checks, I would suggest that your hard drive may by dying.
Your only option now, in my opinion, is to try a completely clean install of the OS.
Obviously you lose a lot of data doing that, but I don't see that you have many other options.
The only other thing would be to get hold of Diskwarrior and see if that can repair things.