Help with my ram

i have motherboard gigabyte GA-MA790FX-DS5 and amd 9850
i have 2 ram of adata ad21066e001gu the motherboard was showing 1066(automatically)
but when i bought 1 ram 2g kingston KHX8500AD2/2G the motherboard shows 667
i tried to take off the 2 adata ram but motherboard shows 800
i tried to change it manually to 1066 but it still show 800(without the 2 adata)

Hi

Like zip said 1066 ram is 800 ram that has been tested to run within the specified voltage range at the specified timings. The user must set the timings and voltages to run 1066.

I recenly purchased these sticks KHX8500AD2K2 and they were horrible, sent them back to Newegg for a refund. They were rated at CAS 7 all I got was a screeching noise, same thing at CAS 6. I finally got them stable at 5, 5, 5, 15, 2T=840MHz, no way, wasn't excepting that.
After researching the sticks (what I should have done in the first place) I found I should have bought the sticks w/o the "A" in it,

KHX8500AD2
KHX8500D2

See the difference in the reviews at Newegg.

KHX8500AD2
http://www.newegg.com/Product/Prod [...] 6820104060

KHX8500D2
http://www.newegg.com/Product/Prod [...] 6820104073

My new sticks should be here tomorrow.......