I replaced recently my WiFi access-point at home and because the new AP (a Linksys WRT160n) supports WPA/WPA2 i tried to connect with WPA2 .. I had some stranges messages (in loop) from NetworkManager when trying to connect to the AP :
I was sure that the PSK was correct because i was able to connect with both my eeepc and my e51 nokia mobile phone.
Querying the great oracle (translate to `using google`) told me that a *lot* of people have the same issue with the ipw3945 wireless nic. (independently of the linux distro : CentOS, Fedora, OpenSUSE, Ubuntu .....) but upgrading to a more recent wpa_supplicant (not available in the CentOS repositories !) package solved it for me.
As usual, read carefully instructions present on the CentOS wiki about the yum-plugin-priorities configuration or do like me : disable all third-party repositories and enable them only when wanted/needed ;-)