Why did my laptop BSOD?

Had posted this in another thread, but it had become confusing, so to make it a more direction question, can anyone see why my laptop has been crashing lately?

It happens after its been left on for a while (>1 hour), but doesn't need to be doing anything for it to happen - once happened on the Win 7 Login screen!



Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 2057

Additional information about the problem:
BCCode: 124
BCP1: 0000000000000000
BCP2: FFFFFA8004E6B038
BCP3: 0000000000000000
BCP4: 0000000000000000
OS Version: 6_1_7600
Service Pack: 0_0
Product: 256_1

Files that help describe the problem:
C:WindowsMinidump112210-17877-01.dmp
C:UsersPeterAppDataLocalTempWER-120027-0.sysdata.xml

I've attached these files so that someone can take a look, hopefully.


Its an Acer Aspire 7520 running 64bit Windows 7.
Upgrades: 2x2Gb matched pair RAM & a 2nd HDD.
I've checked temps, and they are fine (as discussed in another thread).

Idle CPU 45C, GPU 65C
I've also totally removed any dust from the inside of the system using compressed air and replaced the standard thermal paste with Artic Silver 5, although the heatpad on the chipset(GPU) couldn't be replaced this way.


Happy to answer any questions on my setup etc.

TIA