PC Crashes while in sleep - Started recently

Recently, I have been leaving my PC on a windowed game that isn't really CPU/GPU intensive at all. First four days of leaving it on this game my PC was fine, it came through the night, however the past 3 nights my PC has crashed different times throughout the nights and all data I had on the game lost. I also have a memdump from a program called WhoCrashed, ill post below along with my system specs.

Microsoft Windows: 7 Ultimate 32bit
Intel Core 2 Duo Processor
4GB DDR2 RAM
GeForce 8800 GTS 320MB
Foxconn Motherboard P4M900-8237A

Code:

On Thu 27/09/2012 03:25:20 GMT your computer crashed
crash dump file: C:\Windows\Minidump\092712-41730-01.dmp
This was probably caused by the following module: nvlddmkm.sys (nvlddmkm+0x3C8169) 
Bugcheck code: 0x122 (0xA, 0x4, 0x0, 0x0)
Error: WHEA_INTERNAL_ERROR
file path: C:\Windows\system32\drivers\nvlddmkm.sys
product: NVIDIA Windows Kernel Mode Driver, Version 306.23 
company: NVIDIA Corporation
description: NVIDIA Windows Kernel Mode Driver, Version 306.23 
Bug check description: This bug check indicates that an internal error in the Windows Hardware Error Architecture (WHEA) has occurred. Errors can result from a bug in the implementation of a platform-specific hardware error driver (PSHED) plug-in supplied by a vendor, the firmware implementation of error records, or the firmware implementation of error injection.
This is likely to be caused by a hardware problem problem. This problem might be caused by a thermal issue. 
A third party driver was identified as the probable root cause of this system error. It is suggested you look for an update for the following driver: nvlddmkm.sys (NVIDIA Windows Kernel Mode Driver, Version 306.23 , NVIDIA Corporation). 
Google query: nvlddmkm.sys NVIDIA Corporation WHEA_INTERNAL_ERROR

Im unaware of any BSOD's, but my PC is set to not restart once I get BSOD, so I strongly doubt its that. Previous to the latest crash I updated my graphics card drivers, and attempted to research into this issue, finding nothing.

Would appreciate any and all help!

EDIT: Just found another more recent memdump:

Code:

On Mon 01/10/2012 08:41:05 GMT your computer crashed
crash dump file: C:\Windows\Minidump\100112-34304-01.dmp
This was probably caused by the following module: dxgkrnl.sys (dxgkrnl+0x8CC26) 
Bugcheck code: 0x116 (0xFFFFFFFF86119008, 0xFFFFFFFF95938FE6, 0x0, 0xD)
Error: VIDEO_TDR_ERROR
file path: C:\Windows\system32\drivers\dxgkrnl.sys
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: DirectX Graphics Kernel
Bug check description: This indicates that an attempt to reset the display driver and recover from a timeout failed. 
The crash took place in a standard Microsoft module. Your system configuration may be incorrect. Possibly this problem is caused by another driver on your system which cannot be identified at this time.

Not really good at technical stuff mate, thats my biggest worry.