My Mac Pro has recently started having problems turning on. I'll press the start button, then it turns on for a couple of seconds, then turns off, then turns on again, then off, this goes on for maybe 5 or 10 minutes, then it starts up. I've reset the SMC using both methods in article HT1806, but that has no affect. My boot rom version is MP11.005C.B08. I downloaded the latest firmware 1.3, but when I tried to install it, I received a message that my computer did not require it. I did the extended hardware check using my Mac Pro install disk and it reported no hardware problems. This is the first problem Ive had with my Mac Pro since I bought it 4 years ago. Does anyone know what the problem might be? Thanks.