huh where u heard from...probably u need higher voltage when u oc to run at higher speed and tight timing..but if normal u no need to overvolt wan....just run at default as it come will be enuf..

Thats rubbish, even though its a high performance RAM the voltage didnt need to be raised at stock clock, unless you heavily overclock it.

Go to BIOS and try to relaxed the memory timing to 5-5-5-18

U onli overvolt when ur ram is unstable, unstable when u tighthen the timings or at high frequency...Of coz, i would suggest u raise ur voltage around 2.8 v b4 overclock.. THis can burn-in ur ram, which able to make ur ram more overclockable, some says itz a myth...

However, any voltage above 3 v is not recommended unless ur ram stated it can run at tat voltage..Also need to note that which chipset ur ram consist, as different chipset has different potential on the overclockabilty with higher voltage

he's using DDR2 which maybe the RAM already died in 2.8v 

Your restart problem is probably not caused by voltage you used in your memory.  What PSU are you using?  ICUTE?

Misconception.

Any kind of RAM has its own rated operating voltage. It should run at the rated voltage or other wise you can consider it to be faulty and you may request for RMA or replacement from the distributor.

Overclockers only overvolt the RAM over its rate specification for overclocking purpose. Higher voltage is required when a higher speed is unstable. However there is always a certain tolerable voltage for each kind of RAM depends on the characteristic of the chips used. Some may not like higher voltage but some may love to feed on it.

Try to borrow your friend's PSU for like 2 days and use like normal.  If the problem persists, you know it isn't the PSU.  PSU problems is one of the problems people overlook.  Is the PSU new or used?