WOW locks up durring game play

OK, this has been going on sporadically for several months now. It is extremely frustrating. I will be playing World of Warcraft (which I have done for 2 years now on this same machine with no issues) and my computer will completely freeze. When this occurs I get a buzzing sound (coming from the speakers) and the computer freezes. This sound varies in amplitude from occurence to occurence, but never in pitch. The only way to recover is to turn the computer off and reboot. The problem apears to be completely random and I have shut off all non essential processes (I think) and the problem still occurs. I have run hijack this and all sorts of anti-spyware / virus checks and the system appears to be clean. This is the only problem I ever have with this computer. I have the latest drivers for my video card and have latest version of direct x. I have looked at event viewer after this crash and there appears to be this error msg:

Event Type: Error
Event Source: ati2mtag
Event Category: CRT
Event ID: 45062
Date: 10/26/2007
Time: 5:31:22 PM
User: N/A
Computer: KIT-Z0RIWZO3QF4
Description:
CRT invalid display type
Data:
0000: 00 00 00 00 01 00 5a 00 ......Z.
0008: 2c 00 00 00 06 b0 00 c0 ,....°.À
0010: 00 00 00 00 00 00 00 00 ........
0018: 00 00 00 00 00 00 00 00 ........
0020: 00 00 00 00 00 00 00 00 ........


Is this an issue with my video card??
I have included dxdiag report below (not whole thing as it's kinda lengthy, but i can if needed).

Please Help. THANKS!!!!

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System Information
------------------
Time of this report: 10/26/2007, 17:53:58
Machine name: KIT-Z0RIWZO3QF4
Operating System: Windows XP Professional (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_rtm.040803-2158)
Language: English (Regional Setting: English)
System Manufacturer: VIA Technologies, Inc.
System Model: P4M266A-8235
BIOS: Phoenix - AwardBIOS v6.00PG
Processor: Intel(R) Pentium(R) 4 CPU 1.80GHz
Memory: 512MB RAM
Page File: 273MB used, 976MB available
Windows Dir: D:\WINDOWS
DirectX Version: DirectX 9.0c (4.09.0000.0904)
DX Setup Parameters: Not found
DxDiag Version: 5.03.2600.2180 32bit Unicode


---------------
Display Devices
---------------
Card name: ATI Radeon 9550 / X1050 Series
Manufacturer: ATI Technologies Inc.
Chip type: ATI Radeon Graphics Processor AGP (0x4153)
DAC type: Internal DAC(400MHz)
Device Key: Enum\PCI\VEN_1002&DEV_4153&SUBSYS_04021002&REV_00
Display Memory: 256.0 MB
Current Mode: 1024 x 768 (32 bit) (60Hz)
Monitor: Plug and Play Monitor
Monitor Max Res: 1600,1200
Driver Name: ati2dvag.dll
Driver Version: 6.14.0010.6727 (English)
DDI Version: 9 (or higher)
Driver Attributes: Final Retail
Driver Date/Size: 9/28/2007 23:06:17, 268800 bytes
WHQL Logo'd: n/a
WHQL Date Stamp: n/a
VDD: n/a
Mini VDD: ati2mtag.sys
Mini VDD Date: 9/28/2007 23:05:59, 2456064 bytes
Device Identifier: {D7B71EE2-0213-11CF-F569-0824A1C2CB35}
Vendor ID: 0x1002
Device ID: 0x4153
SubSys ID: 0x04021002
Revision ID: 0x0000
Revision ID: 0x0000
Video Accel: ModeMPEG2_C ModeMPEG2_D ModeWMV8_B ModeWMV8_A ModeWMV9_B ModeWMV9_A
Deinterlace Caps: {6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(YUY2,YUY2) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
{3C5323C1-6FB7-44F5-9081-056BF2EE449D}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{552C0DAD-CCBC-420B-83C8-74943CF9F1A6}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,2) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{6E8329FF-B642-418B-BCF0-BCB6591E255F}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,1) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_PixelAdaptive
{335AA36E-7884-43A4-9C91-7F87FAF3E37E}: Format(In/Out)=(NV12,0x3231564e) Frames(Prev/Fwd/Back)=(0,0,0) Caps=VideoProcess_YUV2RGB VideoProcess_StretchX VideoProcess_StretchY DeinterlaceTech_BOBVerticalStretch
Registry: OK
DDraw Status: Enabled
D3D Status: Enabled
AGP Status: Enabled
DDraw Test Result: Not run
D3D7 Test Result: Not run
D3D8 Test Result: Not run
D3D9 Test Result: Not run