I have 2 30" acd's connected to my 2008 mac pro and one constantly keeps turning on and off by itself. After about a minute it powers off and then 10 seconds later it powers back on. Over and over again. Its not the dvi port because i've switched the monitors and its the same monitor that keeps doing it. Has anyone else experienced this? I've unplugged it from the current surge protector into a different one but its not making a difference. There are no usb devices attached to the back of it either.