The reason it is listed as a PCI device is because it is using a PCI bus (even though it is not a 'PCI card') which is normal.
While bucky ball returns, please try this:
then retry connecting. If that works we'll make this change permanent. If not, then please download and run 'wireless_script' (courtesy wild man, dave and others who contributed) as follows :
sudo modprobe -rfv ath5k
sudo modprobe -v ath5k nohwcrypt=1
and post back the contents of the "netinfo.txt" file it creates in your home directory. It will give us a detailed info about your wireless settings.
Please post your output codes within [ code] .. and .. [ /code] tags to put them in a nice box as above. It also preserves the output formatting. To do so, just click on # at the edit box to auto-generate the tags, then copy-paste the output in-between the tags.