2.1ghz iMac Kernel Panics and no CD startup

Question

Just got my Refurb iMac G5. Its 2.1ghz, the iSight model. I chose the Apple Certified Refurb because I work alot with Adobe Creative suite and heard that it wouldnt be UB for at least 2 years by which time I will have a new system.
Anyhow, I bought a 1gb Samsung memory stick from OWC and have been getting Kernel Panics(6 in the last two days). Funny thing is, even when I removed the memory stick I still get the KP's. Secondly, my iMac will not strtup from the Applecare CD. I just get the gray screen with the circle slash through it.
Back to the memory, I ran Disk Utility while booted from the startup disk and it showed a catalog error which Disk Utility could not repair, even when booted from the OSX install DVD. During this time period some crazy stuff was happenning, the computer would NOT startup at all, from strtup disk or cd drive. It wouldget to the Apple logo with the progress spinner under it and then just go black and shut off. It did this probably 15 out of 20 times during an hour. I then got it to finally start up by booting into the black screen with white type (forget hat it is called, single user or verbose or safe...?) ran fsck -f, which showed the same catalog error as before and said it still couldn't fix it. Finally got it to start up; So, I backed up all my files and zeroed out the whole 250gb drive and reinstalled OSX, ran all the Software Updates to get to 10.4.7 and am still getting Kernel Panics, and it still wont start up from the AppleCare cd.
My questions are:
I thought Samsung memory was Apple approved, what should I put in this iMac?
Is there a known issue with 10.4.7 and iMac G5's with KP's?
BTW, I ran Apple hardware test( the LONG one) and everything passed, even the RAM.
Disk Utility now shows a verified and "ok" drive when I test it now; yet still I get KP's
Thanks for any help, sorry for the long post but I wanted to assure clarity in my situation.
offtopic- When I tried to enroll my iMac for my Apple care it told me I need to call Apple, any idea why? I bought the iMac and the Applecare on the same invoice.

Answer 1

Hi swizcore, welcome to Discussions. Do you have any USB or Firewire devices connected to your Imac? These can sometime cause problem start ups. Try if possible to disconnect all but the USB keyboard and mouse and restart.
As for memory most brands of RAM will work, more important is it the correct RAM for your Imac. The fact that you removed it and all that was in the Imac was apple (Hardwired RAM I beleive with iSights) I don't think it would be the problem YET
I would definately be getting a hold of Apple ASAP this should not be happening and at the same time you can get the Apple care registered.
Good luck and post back with results or if they don't find the problem. Bob :~))
Imac G5 Rev B 20   Mac OS X (10.4.6)