I worked with someone on a G4 MYSTIC model. Trying to get OS 9 working. OS X was already working fine. It had a 1.2ghz CPU. It would hang early in Mac OS 9.2.2 startup. Switching to stock 450mhz CPU fixed hanging. NOT SURE WHY! The 1.2ghz ended up working fine (so far) with a different system folder. Why so? In what way would software corruption affect only some clock speed?