DRIVER_DRIVER_STATE_FAILURE 0x09f driver fault stop error caused by ACPI.sys

I've been getting this BSOD on and off for a while now. As far as I can tell, the ACPI.sys driver is at fault. I've asked for help on multiple forums and I've been told that it could be due to many things (BIOS bug, corrupt ACPI.sys file etc.). I figured I'd ask here as well. Here's a copy of the minidump from the latest BSOD.

Microsoft (R) Windows Debugger Version 6.12.0002.633 AMD64 Copyright (c) Microsoft Corporation. All rights reserved. Loading Dump File [C:\Windows\Minidump\110111-13650-01.dmp] Mini Kernel Dump File: Only registers and stack trace are available Symbol search path is: SRV*DownstreamStore*http://msdl.microsoft.com/download/symbols Executable search path is: Windows 7 Kernel Version 7601 (Service Pack 1) MP (8 procs) Free x64 Product: WinNt, suite: TerminalServer SingleUserTS Personal Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506 Machine Name: Kernel base = 0xfffff800`01e4f000 PsLoadedModuleList = 0xfffff800`02094670 Debug session time: Tue Nov  1 03:34:36.278 2011 (UTC - 4:00) System Uptime: 0 days 0:12:32.667 Loading Kernel Symbols ............................................................... ................................................................ ............................................ Loading User Symbols Loading unloaded module list ....... ******************************************************************************* *                                                                             * *                        Bugcheck Analysis                                    * *                                                                             * ******************************************************************************* Use !analyze -v to get detailed debugging information. BugCheck 9F, {3, fffffa800dab0060, fffff80003484748, fffffa8011598e10} Unable to load image nvlddmkm.sys, Win32 error 0n2 *** WARNING: Unable to verify timestamp for nvlddmkm.sys *** ERROR: Module load completed but symbols could not be loaded for nvlddmkm.sys Probably caused by : ACPI.sys Followup: MachineOwner --------- 0: kd> !analyze -v ******************************************************************************* *                                                                             * *                        Bugcheck Analysis                                    * *                                                                             * ******************************************************************************* DRIVER_POWER_STATE_FAILURE (9f) A driver is causing an inconsistent power state. Arguments: Arg1: 0000000000000003, A device object has been blocking an Irp for too long a time Arg2: fffffa800dab0060, Physical Device Object of the stack Arg3: fffff80003484748, Functional Device Object of the stack Arg4: fffffa8011598e10, The blocked IRP Debugging Details: ------------------ DRVPOWERSTATE_SUBCODE:  3 IRP_ADDRESS:  fffffa8011598e10 DEVICE_OBJECT: fffffa800daaf790 DRIVER_OBJECT: fffffa800d032b70 IMAGE_NAME:  ACPI.sys DEBUG_FLR_IMAGE_TIMESTAMP:  4ce79294 MODULE_NAME: ACPI FAULTING_MODULE: fffff88000f72000 ACPI CUSTOMER_CRASH_COUNT:  1 DEFAULT_BUCKET_ID:  VISTA_DRIVER_FAULT BUGCHECK_STR:  0x9F PROCESS_NAME:  System CURRENT_IRQL:  2 STACK_TEXT:   fffff800`034846f8 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : nt!KeBugCheckEx STACK_COMMAND:  kb FOLLOWUP_NAME:  MachineOwner FAILURE_BUCKET_ID:  X64_0x9F_3_IMAGE_ACPI.sys BUCKET_ID:  X64_0x9F_3_IMAGE_ACPI.sys Followup: MachineOwner ---------

My system specs:

Alienware M17x R3

Intel Core i7 2630QM

16BG 1333MHz DDR3

nVidia GeForce GTX 460M

120GB OCZ Agility 3 SSD

320GB Seagate HDD

Windows 7 Home Premium Alienware OEM

Any help will be much appreciated.