Comment 14 for bug 277634

Does the problem only occur with 11N networks? I haven't had any issues with my 4965AGN card on 11g networks, but with the only 11n I've found I can't get a dhcp address (see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/305338).

If the dropouts are only happening on 11n networks, maybe it's worth disabling 11n in iwlagn and seeing if this stops the dropouts:

sudo modprobe -r iwlagn && sudo modprobe iwlagn 11n_disable=1

or add 'options iwlagn 11n_disable=1' to /etc/modprobe.d/options to make it permanent.