I'm running 10.6.5 on my imac and cannot find a way to erase my hd. In disk utility the option to erase is grayed out. I tried rebooting from the snow leopard disk and after I choose my language and click the --> it doesn't show the utilities button. It shows continue, the <--, and mentions something about using the utilities menu to erase.. but doesn't show the actual utilities option. Any ideas?