Blue Screen Problems?

Hi all. Ok i know this get discussed allot but everyone gets different codes etc...

I was wondering if i can get some assistants with mine.

I'm running Windows 7 Professional 32 Bit Dell Version.
PC Spec is:

Case: Antec 900
Motherboard: Gigabyte GA-EP43-DS3
CPU: Intel Core 2 Quad Q9550 Stable overclock to 3.4 GHz
Memory: Corsair XMS2 1066 DDR2 5-5-5-15 2.1v - 2.5v Total of 4GB
Memory Cooler: Corsair Twin Fan
Graphics: ATI Radeon Sapphire HD 4850 x 2 Crossfired
CPU Cooler: Corsair H70 watercooled system
Sound Card: Creative Fatality XFI

I have also run memory tests and all is fine with now errors.

All drivers are up to date and as far as i know windows 7 compatible.

Here are the error messages:

mp File : 122710-24226-01.dmp
Crash Time : 27/12/2010 16:43:22
Bug Check String : PAGE_FAULT_IN_NONPAGED_AREA
Bug Check Code : 0x00000050
Parameter 1 : 0xcd1b221d
Parameter 2 : 0x00000001
Parameter 3 : 0x8b64646e
Parameter 4 : 0x00000002
Caused By Driver : halmacpi.dll
Caused By Address : halmacpi.dll+fd98
File Description : Hardware Abstraction Layer DLL
Product Name : Microsoft® Windows® Operating System
Company : Microsoft Corporation
File Version : 6.1.7600.16385 (win7_rtm.090713-1255)
Processor : 32-bit
Computer Name :
Full Path : C:\Windows\Minidump\122710-24226-01.dmp
Processors Count : 4
Major Version : 15
Minor Version : 7600


And Most common:


Dump File : 122610-26754-01.dmp
Crash Time : 26/12/2010 13:29:34
Bug Check String : IRQL_NOT_LESS_OR_EQUAL
Bug Check Code : 0x0000000a
Parameter 1 : 0x00000008
Parameter 2 : 0x00000002
Parameter 3 : 0x00000001
Parameter 4 : 0x83ab1178
Caused By Driver : halmacpi.dll
Caused By Address : halmacpi.dll+5ba9
File Description : Hardware Abstraction Layer DLL
Product Name : Microsoft® Windows® Operating System
Company : Microsoft Corporation
File Version : 6.1.7600.16385 (win7_rtm.090713-1255)
Processor : 32-bit
Computer Name :
Full Path : C:\Windows\Minidump\122610-26754-01.dmp
Processors Count : 4
Major Version : 15
Minor Version : 7600


Iv just downloaded the halmacpi.dll file off a site to see if that helps but if theres any ideas it would b great to hear them.


Many thanks
Paul