I have 2 kits of this: http://www.newegg.com/Product/Product.aspx?Item=N82E16820104098 I had 1 kit when I had the AM2 5000+ Black and so only ran the ram at 800mhz. I bought a 2nd kit when I bought my Kuma but the 1066 speed is not happening. I have messed with the bios up and down and can get it to run 1066 for 1 whole pass of memtest, but it errors out the 2nd time around every time. I read I may be able to get stable at 1066 with only 2 sticks of ram. Can any other AM2+ owners chime in here. Will I be wasting my time trying to get 1066? If I can get 1066Mhz will 4Gbs of it be better then 8Gbs @ 800Mhz? 64bit Vista, just surf and game, no video editing etc, not even a printer, lol.