Finally I've got 3.2Ghz stable (400x8 | 1:1)with this config:

JumperFree Configuration Settings
AI Overclocking: Manual
CPU Ratio Control: Manual
FSB Frequency: 400
PCI-E Frequency: 100
DRAM Frequency: DDR2-800
DRAM Timing Control: Manual
CAS# Latency: 4
RAS# to CAS# Delay: 4
RAS# Precharge: 4
RAS# Activate to Precharge: 12
TWR: auto
TRFC: auto
TWTR: auto
TRRD: auto
TRTP: auto
DRAM Static Read Control: Disabled

Transaction Booster: Auto
Clock Over-Charging Mode: Auto
CPU Spread Spectrum: Disabled
PCIE Spread Spectrum: Disabled

CPU Voltage: 1'525v
CPU Voltage Damper: Enabled
CPU PLL Voltage: 1.50
DRAM Voltage: 2.1v
FSB Termination Voltage: 1.30
North Bridge Voltage: 1.4
North Bridge Voltage Reference: AUTO
South Bridge Voltage: AUTO

Advance CPU Settings
CPU Ratio Control: Manual
C1E Suppport: Disabled
Max CPUID Value Limit: Disabled
Vanderpool Technology: Disabled
CPU TM Function: Disabled
Execute Disable Bit: Disabled
PECI: Disabled

USB Configuration
USB Functions: Enabled
Legacy USB Support: Enabled


I've had to raise the vCore to 1'525 in Bios (1'5v in Everest). Is this too voltage? If you notice in CPU-Z the vCore is 1'238v... Why?
As you can see the core temps working hard (orthos) reached a maximum of 60C, being always between 55-60C (45 on idle).

Well, I hope that this PC remain stable with the Mac OSX86 I'm going to install before Christmas...

Thanks for all Sesdave and all those who shares his knowledge...