Heres a thing; had it for about a month. iMac8,1, Processor - Intel Core 2 Duo, Speed - 2.66 GHz, running 10.6.6, bout 2 yrs old. Came back to computer after being away for an hour or so, machine took forever to wake up, then spinning beach ball on Word prog, cursor moved normally on screen and dock, clicks produced no results, but extended area of spinning beach ball, no luck with force quit process. After about three or four minutes screen reacted to the first of my clicks, could bear it no longer and switched with power button and restarted file and question mark icon. Restarted with Snow Leopard Disk and went to Disk Utility which declined to recognize hard disc, described it a Media with 0 bytes. Rebooted, tried again, same thing. Did what I had to do on my wife iBook (brand new), came back to my machine, rebooted, successful, but system slow. System seemed fine next day, but became miserably slow with same symptoms as before, including not recognizing startup disc and not seeing HD when started from CD. Curious thing is that my wifes iBook exhibited same symptom on one occasion recently, but not since. Any ideas? Any little tests I can do to locate source of problem?