hi. i have an iMac 333 mhz. and i cannot make it boot from the hard disk. i tried changing the hard drive and RAM. i can boot from the cd, so that should at least say that the RAM is ok, right? i can initialize the HD and i could start the installation and the installation ends successfully. but after restarting, i get this happy mac/question mark blinking picture. would love any tips from you guys how to troubleshoot this problem.