(X)ubuntu 11.10 Modem-Manager gets timeout connecting to t-mobile with usb-gsm-modem huwawei e220

When connecting to t-mobile with a huawei e220 usb gsm modem, i see an error message in syslog

Nov  6 12:01:54 intel NetworkManager[3269]: <info> (ttyUSB0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Nov  6 12:01:54 intel NetworkManager[3269]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889)
Nov  6 12:01:54 intel NetworkManager[3269]: <info> Unmanaged Device found; state CONNECTED forced. (see http://bugs.launchpad.net/bugs/191889)
Nov  6 12:01:54 intel NetworkManager[3269]: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) scheduled...
Nov  6 12:01:54 intel NetworkManager[3269]: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) started...
Nov  6 12:01:54 intel NetworkManager[3269]: <info> Activation (ttyUSB0) Stage 1 of 5 (Device Prepare) complete.
Nov  6 12:01:54 intel modem-manager[2742]: <info>  (ttyUSB0) opening serial port...
Nov  6 12:01:54 intel modem-manager[2742]: <info>  Modem /org/freedesktop/ModemManager/Modems/0: state changed (disabled -> enabling)
Nov  6 12:01:55 intel modem-manager[2742]: <info>  (ttyUSB1) opening serial port...
Nov  6 12:01:55 intel modem-manager[2742]: Invalid error code: 303
Nov  6 12:01:55 intel modem-manager[2742]: <info>  Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabling -> enabled)
Nov  6 12:01:55 intel NetworkManager[3269]: <info> WWAN now enabled by management service
Nov  6 12:01:55 intel modem-manager[2742]: <info>  Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabled -> registered)
Nov  6 12:02:34 intel NetworkManager[3269]: <warn> GSM connection failed: (32) Serial command timed out

Same Modem ist working with 11.04, but not with 11.10