problem with twin2x2048-5400c4 g v7.1

hi. i have a problem with my twin2x2048-5400c4 g v7.1 kit. my cpu is an e4300, my mobo is evga 650i ultra and my vga bfg 7950 gt. my ram can't do 4 4 4 12 1t/2t @ 667 mhz (not 675 mhz for which is rated) with 1.8 - 2.1 v. i've tried the auto setting, the unlinked setting (ram set at 667) and even the linked setting (sync - ed with the fsb @ 1333 => e4300 runs @ 3000 & ram runs @ 667). at the above settings i only change the latencies from 5 5 5 15 to 4 4 4 12 and left the others set to auto. i even used up to 1.4 v for the "cpu fsb voltage " setting and up to 1.5 v for the "mcp voltage". these are the maximum voltges. when i let the latencies set to auto (spd - 5 5 5 15 1t) my system does't crash and i only have to use 1.2 v for "cpu fsb voltage ", 1.2 v for "mcp voltage" and 1.8 v for the ram. these are the minimum voltages i can use. what can i do? and another question ... this kit is rated for 4 4 4 12 @ 675 mhz. it doesn't say anything about the command rate. is it rated for 1t or 2t?

fsb = 1333 (333 x 4)

ram linked & sync => 333 x 2 = 667

the ram is rated for 675 mhz so it should work.

 

if i set it to 533 (unlinked) it will work @ 533 mhz. then why did i pay the extra money for ddr2 667 when i keep it to ddr2 533?