Comment 37 for bug 75358

The people who test this should try to connect to an AdHoc Network via wpa_supplicant and/or iwconfig so you can see if the problem does also exists in the driver or to confirm, that the bug is only in NM. (What it seems to me, the sg.openwireless.ch site suggests to deactivate NM and to use the iwconfig way.)

For Sorry I can't help check it in Lucid since I don't get my w-lan card to work https://bugs.launchpad.net/ubuntu/+bug/539602
But for Hardy let me know what I can do, eventough I use an Atheros card.