It looks like the problem is related to the ipw2200 driver. I was previously using driver release 1.1.2 (and I think I have tried 1.1.1 without success too).
1.1.3 got released recently and it makes both my WEP and WPA work fine so far (and network-manager thus becomes wonderful). I am going to run more tests in the next days and I will close this bug if no problem appears. Brice -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]