is this normal?

[Master_Shake]

Everything looks great until it gets dark, then i notice problems (check the attachment). i've tried changing things in the control panel and trying different settings in HL2. I didn't notice this problem in CS:Source. any suggestions?

Specs:
Athlon XP 2800+
Asus A7N8X-E Deluxe
ATI Radeon 9600XT
Catalyst 4.11 Driver
1gb ddr ram
120gb sata hard drive

 

[BigDaz]

What's the problem?

 

[Maxi]

Eh? I see no problem with that screenshot.