Wireless Network problems

I have a Netgear wireless router that has been configured
with a WPA PSK key.

My compaq nc6000 see's the wifi network and allows me to
put in the network key, however its does not connect to
the network.!!!

Within Network connections in control panel the wifi
connection has a red cross through it indicating its
unavailable, the one next to the time does not though, but
does display it when the mouse is hovered over it. Its
most strange and frustrating.