Solved my problem with a new hard drive and the retail os x 10.4 install dvd by using target mode and my iBook to remote install. After the install, software update ran and updated my os to 10.4.11 and suddenly all problems have gone away and machine is working. Thanks to all who helped. I never did get an answer to my question, what does "invalid memory access" mean? Now that the machine is working I guess it doesn't matter, still just curious.