I am trying to install YDL 4.0.1 on an iMac - 350 Mhz. It got to the second CD and then gave me a blank screen with a symbol for a file with a flashing question mark in it. I have disconnected all the peripherals and have tried rebooting but all I get is the same symbol. I can't even get the cd out. Anybody help, please. John Vile