Computer enters Sleep Mode

Hi,

I have filed a ticket with support but wondered if anyone else has come across my issue.
I have been using SL for quite some time now, however over the last month it appears to send my computer into sleep mode and I have to shut down my machine to get out of it. Sometimes I just freeze and pixelated coloured lines appear across my screen and it crashes me out of SL. I have tried everything to solve the issue, even reinstalled windows and just installed my ATI drivers and still it does this to me. No other application does this to my machine, does anyone have any ideas what the problem may be? (I have disabled all power saving and hibernation options too) computer specs are below:

Display:
Video Adapter RADEON 9250 - Secondary (256 MB)
Video Adapter RADEON 9250 (256 MB)
3D Accelerator ATI Radeon 9200 Pro (RV280)
Monitor Plug and Play Monitor [NoDB] (CX 161056)
Installed Drivers ati2dvag (6.14.10.6614)

Multimedia:
Audio Adapter SiS 7012 Audio Device

Motherboard Properties:
Product SiS-661

I had downloaded the Catalyst Software Suite and installed.

any help advice would be helpful!

This sounds like classic hardware failure or overheat. Either your vid card or CPU is overheating and the machine is trying to save itself by kicking you out, and shutting itself down or the vid card has burned up and needs to be replaced.

do check your cpu's and gpu's fans, see if they are running when your pc is on. yes it does look like something is overheating or overheated.

Ah, you guys could be right cos recently the fans have been making a lot of noise, like right now they are whurring real loud lol. cheers for that!

Yay. Well not really... I'd get those corrected though asap.