Hey Guys, after some tests i ended on this prime95 stable small and blend

Asus P5K Deluxe BIOS 0902 vdrop mod

3852 (428x9) vcore set on bios 1,45
2x2GB Mushkin Ascent 1066@1141 vmem 2,15

JumperFree Configuration Settings
AI Overclocking: Manual
CPU Ratio Setting: 9
FSB Frequency: 428
PCI-E Frequency: 105
DRAM Frequency: DDR2-1141
DRAM Timing Control: Manual
CAS# Latency: 5
RAS# to CAS# Delay: 5
RAS# Pre Time: 5
RAS# ACT Time: 15
TWR: Auto
TRFC: 55
WTR: Auto
TRRD:Auto
TRTP: Auto
DRAM Static Read Control: Enabled

Transaction Booster: Auto

CPU Voltage: 1.45
CPU PLL Voltage: 1.50
FSB Termination Voltage: 1.30
Dram Voltage: 2.15
NB Voltage: 1.4
SB Voltage: 1.05
Clock Over-Charging Voltage: Auto
Load-Line Calibration: Enabled
CPU GTL Voltage Reference: 0.63
NB GTL Voltage Reference: 0.67
CPU Spread Spectrum: Disabled
PCIE Spread Spectrum: Disabled
CPU Clock Skew: Auto
NB Clock Skew: Auto

Cheers
Sergio