Help increasing voltage to Memory

[Black104]

Ok - I work in 3d animation just finished building my new comp,
got win XP 64bit runnin with just 2 gigs @ in 1 slot --

my 64bit apps (3dsmax 64bit/softimage XSI 64bit) ran good, today i threw in another
2 gigs (total 4 gigs) and now they running a little sketchy ran memtest with no errors.

I have another 4 gigs i havn't thrown in yet.

Now I'm guessing its the ram causing the problems because at work i threw in 6gigs on another computer (MB set to 1.8V also) and my 3d apps are acting the same way (sketchy).

I'm gonna need a little walk-through since i've never done this before and i don't want to kill my ram.

I am dealing with the same ram at work and at home --

CPU is Q6600 @ stock speeds.
MB is GIGABYTE GA-P35-DS4 (rev. 2.1)

CORSAIR 4GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) X 2
Here is the info from CPU-Z:

Chipset & Memory

Module 1 DDR2, PC2-6400 (400 MHz), 2048 MBytes, Corsair
Module 2 DDR2, PC2-6400 (400 MHz), 2048 MBytes, Corsair

Northbridge Intel P35/G33/G31 rev. A2
Southbridge Intel 82801IR (ICH9R) rev. 02

Memory Type DDR2
Memory Size 4096 MBytes
Memory Frequency 400.0 MHz (2:3)
CAS# Latency (tCL) 5.0 clocks
RAS# to CAS# (tRCD) 5 clocks
RAS# Precharge (tRP) 5 clocks
Cycle Time (tRAS) 18 clocks
Command Rate (CR) 2T

FSBRAM 2:3

Voltage 1.8V

Corsair specs says : Tested at JEDEC standard latency settings (5-5-5-18) at 1.9V

So waht do you guys think??

Should i be upping the voltage??

Now i dont want to over-clock my ram i just want it to run like it should.

Thanks!
Black