Due to a regression bug in usb-modeswitch, the internetstick isn’t recognized as 3g-modem anymore. This is due to the fact that the stick presents itself as plain usb-stick. It should be unmounted by usb-modeswitch after the driver has been installed (though it works out of the box).
Simply umount the usb datadisk in nautilus en the pincode popup will show!
https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/992639