Comment 31 for bug 468741

After reading the original report, I don't think this is a duplicate of bug #446394, although it seems that some comments in it probably do belong to #446394.

Could this be an 11n issue? My Ubuntu 9.10 can connect to a hidden 11n network at work, but previous versions of Ubuntu to get it to work I had to disable the 11n functionality in my intel 4965 card by adding a file /etc/modprobe.d/iwlagn.conf with the line:

options iwlagn 11n_disable=1

and then restarting the network card with:

sudo modprobe -r iwlagn && sudo modprobe iwlagn

I've done this again in Ubuntu 9.10 recently because either network-manager or the 11n driver is still a bit buggy (after connecting to the hidden 11n network, when I standby and resume and try to connect to my home 11g network, it often can't connect).