Gigabyte GA-P55-US3L P55 Socket 1156 8 Channel Audio ATX Motherboard
Intel Core i5 750 2.66GHz Socket LGA1156 8MB L3 Cache Retail Boxed
Crucial 4GB (2x2GB) DDR3 1600 i5 Memory Kit CL9 1.65V
ATI HD 5770 1GB GDDR5 Dual DVI HDMI Display Port Out PCI-E Graphics Card OEM
Corsair 650W TX Series PSU

I am running Windows 7 64 bit on a 64GB SSD, and have a Samsung F3 as a data drive. I updated the BIOS to the latest version and this has not solved the issue.

Running intensive tasks the system works fine, as soon as you stop and run idle or broswe net/music etc you get random freeze, can happen at any moment really.

I RMA'd the motherboard back to the seller, but I have just been informed the item is being sent back to me, as no fault can be found.

Is there something I doing wrong with the settings? Or is there a compatibility issue I am now picking up on?

You RMA'd what back? Random crashes can be caused by many things - the motherboard, CPU, RAM, PSU. Even the graphics card. And since you are using a SSD, that could cause it too. So what did you send back?

Heat is also a common cause but since you said it does not do it when heavily tasked, it does not sound like a heat problem.

Did this system ever work right, or have you had problems since day 1?

If since day 1, you need to be 200% sure you don't have any extra standoffs under the motherboard causing an intermittent short. You might try one stick of RAM at a time too.

Well spotted on the item i sent back... i have edited the post.

To clarify i sent back the motherboard Gigabyte GA-P55-US3L.

I have tried many scenarios with the system, i have tried it with just 2GB ram, up'ed the voltage, installed the cayalyst drivers for the graphics, just installed the graphics driver from Windows Update. Tried all the bios updates, wiped the system, taken the board out re seated CPU, RAM etc

It is hard to tell whether it has been problematic since day one... the easiest answer would be to say yes.

up'ed the voltage

Return and leave all voltages in their default settings until this is resolved.

When you tried it with just 1 stick of RAM, did you try one, then swap it out with the other?

Do you have a proper application of TIM?

At this point, I would probably remove everything from the case and set the system up on a breadboard or something similar. Use only 1 stick of RAM and I would skip the SSD too, and try a HD and see if it all holds.

And while Corsair PSUs have become one of my personal favorites, even the best can have problems.

Upping the voltage made the system less stable, in some instances would not even boot... so i cleared the CMOS and started fresh from default.

The TIM was already applied to the stock cooler. I really do not envisage any problems with the TIM as i can run intensive applications without fail, only when the system is broswing web,/iTunes or idle the random crashes occur. The temps do not get overly high, even on 100% load using testing software.

I have been reading on another forum of a similar problem with a very similar spec PC, the wireless adaptor was mentioned... i have disabled and uninstalled and this has had no effect.

I have ordered some OCZ ram... i will test this when the motherboard returns to me... see if the same thing happens.

Keep us posted.