Thx for your quick reply!
Yeah...maybe i need that cable! But why this is happening if in my friends PC with the same mobo, PSU, internal sata HDD's, same sata DVDRW, case, WC system, i don't have this problem?!?! And in other motherboards like DFI P35, eVGA 680i on this same case with same hardware don't have this issues? :shrug:
Anyway...thx! Maybe i'll try the new eVGA 780i SLI motherboard!