Hey, I have a G3 700 MHz iBook. It's been pretty problem free for 3 years. I did have to get the logic board replaced (by the free program). All of a sudden it got rediculously slow. It took literally 30 seconds to recognize mouse clicks. I tried repairing permissions and disk. Even did a harware test. nothing changed. So i decided to go ahead and erase and install os X again. Everything was going fine until there was an error that said "there was an error in instalation process" "try again". now when i restart i get a flashing question mark and prohibitory sign, even when I try to boot from the install CD. eventually it gets there but then there is no HD mounted. Then if I use disk utility to erase the HD (there is none mounted), it shows up and I can install OS X. BUT there is the same instalation error every time (i've tried at least 8 times after trying various things (resetting PMU, PRAM etc.)).
I'm assuming its a hardware problem since the HD was formatted and there is nothing on it. Could it be a hard drive problem or something else?

Any help appreciated.
btw, the latest harware test (logic board, memory) passed.