I am pretty sure I posted abot this here as well as the Apple forums at some point over the past year. I installed more RAM from OWC yesterday and now everytime I try to put my Quad to sleep, it doesn't and the cooling fans go into hyper mode and I have to power off my holding the power button down. I had 2 1 gig RAM chips from OWC installed in slots 3 and 4 with no problem. Now I installed 2 more 1 gig chips in slots 5 and 6 and I have this unable to sleep issue, along with KP's frequently. I had this issue several times before and initially thought it was bad RAM, however this is the 4th set of RAM I am trying with the same results each time. I have several friends who use RAM from OWC with no problems in their Quads interestingly enough. I ran the hardware check as soon as I installed it and it passed with no issues. Could I have a bad RAM slot? Any suggestions? I know others have had this problem as well. Thanks in advance.