I have searched high and low for a solution to getting my internet connection working in Oneiric. It was working perfectly for a long time.
The device is recognised (Nokia N97 or Huawei E620) but when clicking on the network connection a notification IMMEDIATELY pops up saying Activation Failed.
Nothing I've found works.
Syslog is fine up until: GSM connection failed (32) operation not supported From there network-manager goes from preparing the device to halting it again.
---UPDATE--- Fresh install of 12.04. Issue persists after unexpectedly pulling out modem. Sometimes deleting the network connection and re-adding it solves the problem.