1366 motherboards and the memory performance are dependent on the internal memory controller in your CPU - IMC for short.
You will have to find what is the sweet spot for your unique CPU and the memory is. Unlike DDR2 which was a breeze to set up, even to push till smoking, DDR3 tweaking regardless of what the default specification of the ram bought claims on the 1366 platform requires considerable effort to achieve. Some folk just get lucky. Please keep in mind that unlike the i5/i7 platform, which has native support for DDR3 1600 and above some boards up to 2200 Mhz, 1366 does not. Yes you can over-clock your ram to impressive frequencies but it is dependent on the IMC or in other words your over-clock is dependent on your CPU.
Disclaimer - not saying your CPU is bad or borked.
Just giving you some back ground and some hope, namely that with a bit of time and effort you should succeed.