Problems with Hyper Threading

Around one year ago I installed new mother board and
processor in HT technology. For eight months the computer
worked great, but some day, around one month ago, without
any reson my computer started to reboot several times a
day.
First, I was looking for the cause of the restarting by
myself (it wasn't any virus) by formatting the hard drive,
reinstalling the windows and after two weeks I gave the
computer to the computer shop. For 4 weeks overthere they
were checking every element by replacing it for new,
including MB, CPU, HDD, Sound C, Video C, CD,..etc, etc.
and nothing changed.
Finally someone decided to disable Hyper Threading in
BIOS and my computer started to work properly. But they
coudn't find any way to resolve the problem..!!!
Almost right after I enable HT in BIOS computer crushes
and appears the information: A problem has been
detected... etc. etc, etc.
IRQL_NOT_LESS_OR_EQUAL
STOP: 0x0000000A ( 0x680c7727, 0x000000FF, 0x00000000,
0x80534A84)

It looks like the problem is in the cooperation MB
with CPU and Windows.
Also, when my computer worked in HT system the processor
temperature was hold around 82 - 86 F, but after turning
off the HT the CPU temperature raised to 130 F.

I hope, you can help me and advise to resolve the
problem.

System ;
Mother Board - ASUS P4C 800 Deluxe-UAY / SN -
34MGOM6875
CPU - P4 / 3GHz / 800MHz / 512 - KB L2 / Hyper
Threading / Prod. Code - BX80532PG3000DSL6WK
Fan - Zelman CNPS7000A - ALCu
RAM - DDR dual-chanel / 4 x Kingston KVR400X64C3A/512
HDD - 1 x - 36GB SATA 10K RPM Western Digital / 8 MB , 3
x - ATA 120GB Wdigital / 8MB
Sound C - SB Audigy 2 ZS
Video C - ATI Radeon 9000 Pro / 64 MB DDR - All in
Wonder
CD-DVD Rom - Samsung SD-616
CD-RW Rom - Liteon 52x24x52
OS - Windows XP Professional Version - 5.1.2600 SP1 Build
2600
BIOS - America Megatrends Inc. 1016.001, 02/23/2004
SMBIOS - Version 2.3

Regards Andre