I'm not sure what happened, but my MacBook Pro has suddenly stopped auto-detecting when a new DVI cable is attached. The monitor is turned on and the right input is selected, but the only way I can get it to work is if I go into the System Preferences, Displays, and then click the Detect Displays button. Does this sound like a software problem or a hardware problem? I'd really appreciate anybody's help.. It's driving me nuts! Thanks!