I have the same bug. Wireless would not connect to 802.11N after upgrade to 12.04.
WORKAROUND: I had to disable N mode with
options iwlwifi 11n_disable=1
in /etc/modprobe.d/disable11n.conf
I did a new install of 12.04 and it seemed to have fixed the problem, however after a couple of days the issue returned and I had to revert to the workaround.
Chili555 over at Ubuntu Forums seems to be the go to guy on this issue.
I have the same bug. Wireless would not connect to 802.11N after upgrade to 12.04.
WORKAROUND: I had to disable N mode with
options iwlwifi 11n_disable=1
in /etc/modprobe. d/disable11n. conf
I did a new install of 12.04 and it seemed to have fixed the problem, however after a couple of days the issue returned and I had to revert to the workaround.
Chili555 over at Ubuntu Forums seems to be the go to guy on this issue.