Wireless not working now

I had the computer running on the network fine, then I took out the wireless PCI card and put it in another computer. That computer worked fine.
Now, I take the adapter out again, put it back in the original computer, it doesnt work anymore. No settings have changed that I can see.
Funny thing is, using static IP it actually says it connects to the network with very good signal strength. It shows packets were transmitted, but none are received. When I try DHCP, it cannot get an address because it cant receive from the router.
The router shows wireless packets transmitted and received.
I thought the card might be buggered, but put it in the other computer again and it works fine.
Any ideas?