WiFi problem on blackbook.

I have a 2.0 C2D blackbook i bought back in june. i upgraded to leopard when it came out. ive had zero problems with it until recently. Some of the wireless networks i normally connect to at clients offices or hotspots don't work anymore. i can connect to them but don't receive dhcp. setting to static doesn't work either. I've searched all over for a similar case with no results.

Edit: Forgot to mention i have the same problem in bootcamp running vista.

system info:

Model Name: MacBook
Model Identifier: MacBook2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 1 GB
Bus Speed: 667 MHz
Boot ROM Version: MB21.00A5.B07
SMC Version: 1.13f3


Wireless Card Type: AirPort Extreme (0x168C, 0x87)
Wireless Card Locale: USA
Wireless Card Firmware Version: 1.2.2

 

ya ive tried that one many times with no luck.