Will someone with a iMac G5 confirm this is also happening on their machine? When I insert the Hardware test CD, the cooling fans go into high gear and they run until that CD is ejected. The fans remain quiet if I insert a music CD. The reason for asking is that I have had several hard freezes (had to shut down with power switch) and all of them were when I had something in the superdrive. So far none of the crashes are repeatable. Once with iTunes, twice while printing from Safari. The last two caused the fans to really crank up and pump out the hot air. Keeping fingers crossed and purchasing Applecare. :-))) Ray Reedy