Driver Power State Failure on Dell Vostro 3550

Hi all. I'm getting a constant BSOD with Driver Power State Failure as the cause. I tried downloading WhoCrashed as suggested on an existing thread here, and here's the info I'm getting:

windows version: Windows 7 Service Pack 1, 6.1, build: 7601
windows dir: C:\Windows
Hardware: Vostro 3550, Dell Inc., (edited for privacy)
CPU: GenuineIntel Intel(R) Core(TM) i5-2430M CPU @ 2.40GHz Intel586, level: 6
4 logical processors, active mask: 15
RAM: 8491417600 total
VM: 2147352576, free: 1921105920

Crash Dump Analysis

Crash dump directory: C:\Windows\Minidump

Crash dumps are enabled on your computer.

On Tue 2/04/14 3:06:39 AM GMT your computer crashed
crash dump file: C:\Windows\Minidump\020314-36785-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x78A8A)
Bugcheck code: 0x1000009F (0x4, 0x258, 0xFFFFFA8006A13660, 0xFFFFF80004DCD3D0)
Error: CUSTOM_ERROR
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.



On Tue 2/04/14 3:06:39 AM GMT your computer crashed
crash dump file: C:\Windows\memory.dmp
This was probably caused by the following module: ntkrnlmp.exe (nt!KeBugCheckEx+0x0)
Bugcheck code: 0x9F (0x4, 0x258, 0xFFFFFA8006A13660, 0xFFFFF80004DCD3D0)
Error: DRIVER_POWER_STATE_FAILURE
Bug check description: This bug check indicates that the driver is in an inconsistent or invalid power state.
This appears to be a typical software driver bug and is not likely to be caused by a hardware problem.
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time.



On Fri 1/31/14 1:00:08 PM GMT your computer crashed
crash dump file: C:\Windows\Minidump\013114-24382-01.dmp
This was probably caused by the following module: ntoskrnl.exe (nt+0x78A8A)
Bugcheck code: 0x1000009F (0x4, 0x258, 0xFFFFFA8006A14660, 0xFFFFF80000B9C3D0)
Error: CUSTOM_ERROR
file path: C:\Windows\system32\ntoskrnl.exe
product: Microsoft® Windows® Operating System
company: Microsoft Corporation
description: NT Kernel & System
The crash took place in the Windows kernel. Possibly this problem is caused by another driver that cannot be identified at this time. 

and so on.. it goes on like that for a bit.

Any suggestions on how to troubleshoot and fix this would be much appreciated. Thanks in advance!