help: volume ownership & permissions cannot be accessed or changed!

I had had troubles infinity with my Power Mac G4 and had successfully installed Leopard but found the troubles continued. Finally I gave up and a computer friend installed two hard disks and Mac OS 10.4. From the beginning I have been using both the internal and an external firewire bootable hard disk with Mac OS 10.4.11. The external hard disk began to crash and I repaired it several times, finally reinstalling (as I did on the internal hard disk). When I checked the external hard disk, it had changed to the afore mentioned Ownership & Permissions. When I couldn't get my mail to work on the internal hard disk which had transfered everything from my successful external had disk, I cloned the external onto the internal. Finally everything worked including mail, so I thought, until I tried address book which led me to discover the whole internal hard disk had changed to the afore-mentioned Ownership & Permissions. Now I have two identical hard disks with the same weird Ownership & Permissions. If the Permissions you have mentioned came from Leopard how could they have gotten into the computer? I don't know. I am not schooled in terminal and fear to take that step unless there is none other available. Sorry for the long answer, but it seems that all of the thread pertains to Leopard which I am not using (I have things on Classic that have not yet been upgraded for Leopard use). Please don't give up on me. Thanks in advance.

Thank you all for your responses. I had two lectures today at the university so I have not yet had a chance to apply any of the solutions except, of course, the logical Disk Utility which all Mac users learn upon purchase. As the disks both can be used with the exception of permissions which restrict access like address book or mail, I will run the ram test even though I don't believe that is the source of the problem. Talking with a computer programmer at the university (who doesn't know Macs, incidentally) I was introduced to the terminal which was suggested in the form (thank you). He was sure that by working through the terminal I could certainly correct the permissions and that I should learn to use the terminal since I know this much about Macs already. So, tonight I will follow the directions given me by the forum and attempt terminal. Wish me luck.

It's close to one in the morning but the terminal attempt was successful (sudo fsaclctl -p /Volumes/Name\ of\ Your\ Hard\ Drive -d)! Hopefully Owner: system and Group: admin both with Read & Write Access are the correct settings to use for both my internal and external bootable disks. If not, please tell me differently. Everything seems to work well so far except Address Book still opens for 2 or 3 seconds and then closes. If there is a thread somewhere that you know of for this remaining problem, I would appreciate knowing. The terminal experience was an eye opener for me and perhaps an invitation to a new exploration of Mac. Anyway, thanks a million one and all (I did try downloading AHT but the file was empty, and Disk Warrior as well as TechTool proved fruitless, thanks anyway). I will test out the disks later and let you know whether everything is as good as it seems -- except for Address Book, that is.