Mods plz move if this is the wrong forum. Issue is display related, but specific to a Mac Pro. I'm having an odd issue with my 23" Cinema Display connected to my 2008 Mac Pro with an ATI 3870 card, running 10.5.6. I have the display set to power down after 10 minutes in the Energy Saver pref pane. Originally, when the display powered down, the white LED in the bezel would come on, and a key press or mouse move would turn the monitor back on. Not too long ago, I started noticing 2 odd behaviors: 1) Sometimes when the display powered down, the white LED would blink. No real regular pattern to the blink. Sometimes it would blink slowly, sometimes erratically. Pressing a key or moving the mouse would turn it back on. 2) Other times, the white LED would completely go off. In this case, the display would NOT turn on after a key press or mouse move. In fact, it seemed completely unresponsive; the power button on the side did nothing either. If I try to sleep the whole machine at this point (Option+Command+Eject hot key), it would sleep then immediately turn back on, but the display would stay off. What's even weirder, in the 2nd case, to get the display to come back on, I either had to 1) do a hard power down of the Mac Pro, or 2) turn on my MacBook Pro. Seems that Bonjour would see the MacBook Pro on the network, and would turn on the display. Anyone ever experience this problem or know how to resolve it? I've tried zapping the PRAM and resetting the SMC, with no luck. Also, the problem doesn't seem to be as bad in Windows XP using Boot Camp. Most of the time the display and its LED would behave properly in this case. Next thing I'm thinking of trying is to swap the graphics card with the stock 2600XT card to see if my 3870 is bad (which I'd really hate because I have one of the quiet ones ).