The bmobile SIM is now working! Huge kudos to "tesuri" who has
shared this settings through his tweets.

As a root user, run the following command:

dbus-send --system --type=method_call --print-reply --dest=com.nokia.phone.net "/com/nokia/csd/gprs" org.freedesktop.DBus.Properties.Set string:com.nokia.csd.GPRS string:AttachMode variant:string:WhenAvailable

The settings will be saved permanently.