P4 640 Won't get past 225 fsb

Hi.

Ive have got a really strange problem here.

My Pentium 4 640 3.2 wont get past 225 fsb seems really strange. Its a M4, Rev. N0 , Step 3.

When it boot with 225 fsb , the monitor just go standby.
When its below 225 (224) it will boot fine.
Giving me speed at 3.58 ghz ! wtf
Trying to raise vcore has no effect what so ever !

Any ideas ?

Motherboard : Asus P5LD2-VM
PSU : 500 watt
RAM : King, 333,

At the default FSB of 200MHz, and using the default 3.33 DRAM multiplier, the effective DRAM frequency is DDR2-667. When you raise the FSB to 225MHz, the effective DRAM frequency is bumped up to DDR2-750. So chances are your DDR2-667 RAM can't run at that high a frequency without either increasing the DRAM voltage or loosening the timings... or both. If you have the option, select the 2.66 DRAM multiplier = DDR2-600 at a FSB of 225MHz.

i can't mess with multiplier. i can only set memory mhz and voltage. i have set memory to 333 mhz

... then set the frequency to either 266MHz or 200MHz. The multipliers are integrated into the available DRAM frequency options.

After googling around the net, i found out that, to raise the fsb over 224, you will have to raise PCI freq. Strangely enough i tryed it and works. Currently running 4.1 ghz. But is waay to unstable, i blame it on the PCI Freq, when i set PCI to 117
or lower screen goes standby and no boot. PCI-Freq raised to to 118 boots fine with 263 FSB. But crash after few hours. I blame the high PCI-freq. Any one have had and problem with this motherboard .

And what the hell does PCI freq have to do with my fsb ?

Asus.P5LD2-VM, Bios 1305 (Newest)

On some motherboards were fsb holes like can boot @220MHz ,can't @230MHz but is running fine at about 240-250MHz. I had it like that on 2 boards. Then I remember I had to pass about 20-30MHz. Check it with lower memory multi etc, maybe will help.