Finally I'm stable with Dominators@1800MHz

BIOS: 0904

Ai Overclock Tuner: [Manual]
OC From CPU Level Up: [Auto]
OC From Memory Level Up: [Auto]
CPU Ratio Setting: [08.0]
FSB Frequency: [450]
FSB Strap to North Bridge: [333MHz]
PCIE Frequency: [100]
DRAM Frequency: [DDR3-1801MHz]
DRAM Command Rate: [1T] (2T works as well of course)
DRAM Timing Control: [Manual]
CAS# Latency: 7
RAS# to CAS# Delay: 7
RAS# Precharge: 7
RAS# Active Time: 20
RAS# to RAS# Delay: 4
Row Refresh Cycle Time: 60
Write Recovery Time: 9
Read to precharge time: 6

Read to write delay (S/D): 8
Write to read delay (S): 7
Write to read delay (D): 6
Read to read delay (S): 4
Read to read delay (D): 7
Write to write delay (S): 4
Write to write delay (D): 7
DRAM Static Read Control: [Disabled]
DRAM Dynamic Write Control: [Disabled]
Ai Clock Twister: [Strong]
Ai Clock Skew for Channel A: [Auto]
Ai Clock Skew for Channel B: [Auto]
Ai Transaction Booster: [Enabled]
..........Boost Level: [2]
CPU Voltage: [BIOS: 1.50 Real: 1.48]
CPU PLL Voltage: [BIOS: 1.54 Real: 1.616]
North Bridge Voltage: [BIOS: 1.59 Real: 1.616]
DRAM Voltage: [BIOS: 2.02 Real: 2.096]
FSB Termination Voltage: [BIOS: 1.44 Real: 1.504]
South Bridge Voltage: [BIOS: 1.05 Real: 1.072]
Loadline Calibration: [Enabled]
CPU GTL Reference: [0.63x]
North Bridge GTL Reference: [0.67x]
DDR3 Channel A REF Voltage: [Auto]
DDR3 Channel B REF Voltage: [Auto]
DDR3 Controller REF Voltage: [DDR3_REF]
SB 1.5V Voltage: [BIOS: 1.50 Real: 1.552]
CPU Spread Spectrum: [Disabled]
PCIE Spread Spectrum: [Disabled]


*Advanced CPU Settings

C1E Support: [Disabled]
CPU TM Function: [Disabled]
Vanderpool Technology: [Disabled]
Execute Disable Bit: [Disabled]
Max CPUID Value Limit: [Disabled]

Looks like the Dominators need some overvolting to work @1800MHz with Maximus Extreme...