I think I’ve made an interesting discovery. Sometimes when I’m on the train I loose my connection. Getting it running again could prove diffucult, and, like today, even a reboot of the computer doesn’t really solve everything, since network-manager doesn’t find the 3G card even after I’ve executed usb_modeswitch.
The discovery is pccardctl, and not only that program as such, but that it shouldn’t be executed with sudo. If I do pccardctl seems to hang. So, when encountering problems that cannot be solved by “disconnect / connect” in network manager I think this is the way to go:
take out the card and insert it again.
Then connect through network-manager. I will test this furter as soon as I get a chance with a crashed connection.