A lot of people with Intel wireless cards seem to have issues connecting to hidden networks with NetworkManager. Unfortunately my university only provides wireless through a hidden network. Although of course there’s a handy one that broadcasts its SSID, doesn’t require a login and explains what the SSID of the hidden one is (how this is more secure is beyond me). The problem is that NetworkManager just gives the card the BSSID and it needs the SSID as well, even though it really shouldn’t. This patch applies to head as of the end of 2008 and fixes the issue. Some distributions patch their NetworkManager in order to include something similar to this. This bug has been around for as long as NetworkManager has existed from what I can see, I wonder why it hasn’t been fixed.