I have a slightly unusual issue. I overclocked my memory to 1800mhz 7-7-7-20 2T @ 2.0v. Passed a hours worth of memtest. Now when I load windows, if I open steam and press Alt+F4 to minimize the steam window to the system tray, my system usually freezes with my RAM at these settings. At 6-6-6-18 2T 1.9v 1500mhz I can open steam and press alt+f4 all day long. I tried increasing the voltage to 2.05v and lowering timings as far as 8-8-8-24 but the same thing happens everytime. My setup: Motherboard: Asus Rampage Extreme CPU: Intel Core 2 Duo e8600 overclocked to 4.275ghz, 1.28v (450x9.5) CPU Cooler: Thermalright Ultra 120 Extreme RAM: OCZ FlexXLC PC3-12800 Video: CrossfireX Visiontek 4870 Sound: Asus Xonar D2 PSU: OCZ Elitestream 1000w My NB voltage is at 1.51v which I believe is adequate. My NB GTLVref and DDR3 GTLVref and just about every other memory related setting I did not mention is at Auto - not sure if setting these might have anything to do with it or not. I do believe I have bad RAM, as one stick I can run 5-5-5-15 2T at 1600mhz on at 2.05v and the other needs a full 2.05v to run 6-6-6-18 at 1600mhz, but being that I'm passing memtest for a hour at 1800mhz RAM speed and this problem happens almost everytime I alt+f4 out of steam. But I have no problems at all at 1700mhz (7-7-7-20) or 1600mhz (6-6-6-18) but with a 450mhz FSB speed, I can only set 1500 or 1800mhz. Please help.