Guys:
I quasi had the same problem. On my router at home, the security that is enabled is WPA-PSK, with MAC address filtering, network key, also I have my SSID set to hidden, and tkip encryption. Make sure you enter the MAC address of your ppc on the your router and set the filtering mode to enable, if you put disable it will lock out that wifi connection and any other wifi connection that tries to connect to that router that does not have permission. Set your MAC# ON YOUR PPC IN YOUR ROUTER!!! That way your router will recognize it as being allowed, then it will assign it an IP address. I sincerely hope that this helps. Happy surfing.
Trickyricky