I bought some Kingston RAM from buy.com last week. The memory kit I bought was for a iMac or Macbook. Its DDR3-8500 so I know its the right kind of RAM for my mac mini. BTW, my mini is the late 2009 version with 2.26 C2D, 2GB DDR3-1066 RAM, 160GB HDD. So the ram comes in and I install it. I was extremely careful in how I dismantled the mini. I put it all back together and it boots fine, it shows the new ram installed under system profile. Everything runs great. Except now it will not go into sleep mode on its own after the 10 mins. It did before the RAM swap fine. Under Energy Savings I have it set to put the display into sleep mode after 10 mins. Under screen saver settings its set to bring up the screen saver after 5 mins. I let it go for hours and it wouldnt do either one on its own. Any ideas what could be causing this? Thanks!