noob getting nowhere overclocking e6750

hi all

I'm a complete noobie when it comes to overclocking. I have a rig with a e6750 cpu, a Gigabyte GA-P35-DS3P rev1.0 motherboard, and 4x 1GB Corsair XMS2 DDR2-800 mhz( rated timmings are 4-4-4-12) dual channel RAM.

So i read the overclock guide on this forum for C2Q and C2D, and fought I had it figured out(turns out I was wrong).

trying to do some overclocking i did the following:

turn off virtualization technlogy, C1E, etc except for TM2
turn off C.I.A2
set the performance enhancement setting to Standard(possible options are : standard, turbo, extreme)
set voltage control to auto
set PCI-Express freq to 100Mhz
set memory timmings to manual and lax to 5-5-5-18(incase my mem ain't that good)
set fsb to 400mhz(up from 333mhz)
set spd to 2( giving a dual channel memory of 800mhz)

now the system boots to the point where it performs the memory test at which point it halt's for some time and then reboots with old settings.

then tried setting the fsb to 350mhz (with spd to 2 giving a dual channel memory of 700mhz)
but with same results.

normally i run my mem at 800mhz 4-4-4-12 so I don't think they are to blame (of course I could be wrong about this)

if some of you have any pointers on what's wrong, it would appreciate it

Memory divider should be 1:1. Is that the spd?

I run a 6750 overclocked to a modest 3ghz on a ga-p35-ds3l board - it will go to 3.2ghz with no voltage increase to cpu. However i found on my board that the default voltage for the memory was not correct and had to up the voltage by 0.3v.So i would check your ddr voltage is actually correct,look on memory or check with supplier then see what your board sets it to.If it is correct and you are overclocking it it may need a slight increase in voltage.
Leave pci-express frequency alone( to start with). (I set my fsb to 375).

a SPD of 2 is the lowest i can choose, and results in DDR2-800 mhz speed, if the fsb is set to 400 mhz. mean while i have, to my surprise, found out that setting the pci-e bus speed to 100Mhz instead of auto results, in the system only successfully passing the post approximately 1 every 10 times, with all other settings set to the optimized defaults. now just changing it to auto makes it post succesfully every time. i'm puzzled by this since 100mhz is suppose to be the standard pci-e bus speed right?

anybody have any ideas ?