I think your problem has something to do with the network manager of Enlightenment. Gnome's network-manager works fine under Ubuntu 10.10 on my laptop as well as on my EEE.

Have a look at the enlightenment forum as it will probably be of more help than talk.maemo.

Edit: If I remember correctly, you need to install the Exalt module in order to work with ad hoc connections in E17. Hope that helps.