Comment 13 for bug 290639

So you want to use a wireless bridge to start a ppoe connection over wireless like the description here: http://mail.gnome.org/archives/networkmanager-list/2008-November/msg00211.html ? I had the same problem when installing Intrepid on some friend's machines who are clients of a popular German provider that usually delivers the combination bridge + ADSL modem.
A possible workaround still using network-manager would be: Connect to the wireless network via n-m, giving yourself any static ip. Then run pppoeconf to configure your pppoe connection. This will change your /etc/network/interfaces so that this interface is not managed in n-m any more. Revert these changes by commenting out all the lines with the interface you configured. Then you can connect with n-m to the network and finally you use 'pon dsl-provider'.