My problem is almost solved.
I bought a CORSAIR Vengeance LPX 4GB 2400 Mhz (CMK4GX4M1A2400C14R) to test and the motherboard worked.
The incompatibility exists in the F4 and F6 BIOS, but it's possible to set in the motherboard the memory clock to 21.33 or 24.00 and the HX426C15FBK2/16 will work. DO NOT set to 26.66 (or anything outside JEDEC) in these BIOS versions, it won't post. DO NOT change CAS values, it won't post, but at least won't reboot each 15 seconds. If you put two different rams (i've tested with this corsair and one hyperx stick) the BIOS auto set the clock to 2133, but in this case it's possible to set to 2400.
With the F7b BIOS (careful, it's a beta BIOS, you can found it in the tweaktown forum) the memory is recognized with defaults parameters and it's set to 2667 Mhz in auto mode, BUT it makes the motherboard crashes AF. So if you want to leave in the F7b I recommend decreasing the clock to 24.00, that way it works flawless.
Then it will stay running with the long beeps right?
No, it reboots after 15 seconds more or less.
Yes the ram should boot and run by the default setting 2133.
It should, but it didn't happened.
Did you look at the CPU socket to seen if you have a bent pin.
Yes, i don't have any bend pin.
Did you test the CPU, Memory, & Video card? Everything runs through your CPU today. Till you know if all those ietms work you really can't tell what is the problem. One of them or the board.
I excluded most of the possible causes, the problem that was left was ram compatibility, and I was right.