Comment 26 for bug 509738

Same behaviors for me. I tried both the versions of lucid and network manager's PPA.*

The reveling lines of debugging outputs :

sudo modem-manager --debug
[..]
** Message: (ttyUSB2) opening serial device...
** Message: Modem /org/freedesktop/ModemManager/Modems/0: state changed (disabled -> enabling)
** (modem-manager:7473): DEBUG: (ttyUSB2): --> 'ATE0 V1<CR>'
** (modem-manager:7473): DEBUG: (ttyUSB2): <-- '<CR><LF>OK<CR><LF>'
** (modem-manager:7473): DEBUG: (ttyUSB2): --> 'AT+CPIN?<CR>'
** (modem-manager:7473): DEBUG: (ttyUSB2): <-- '<CR><LF>+CPIN: SIM PIN<CR><LF><CR><LF>OK<CR><LF>'
** Message: Modem /org/freedesktop/ModemManager/Modems/0: state changed (enabling -> disabled)
[..]

sudo NM_PPP_DEBUG=1 /usr/sbin/NetworkManager --no-daemon
[..]
NetworkManager: <info> Activation (ttyUSB2) starting connection 'SFR 3G+'
NetworkManager: <info> (ttyUSB2): device state change: 3 -> 4 (reason 0)
NetworkManager: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) scheduled...
NetworkManager: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) started...
NetworkManager: <info> Activation (ttyUSB2) Stage 1 of 5 (Device Prepare) complete.
NetworkManager: <WARN> stage1_enable_done(): GSM modem enable failed: (32) SIM PIN required
NetworkManager: <info> (ttyUSB2): device state change: 4 -> 9 (reason 0)
NetworkManager: <info> Marking connection 'SFR 3G+' invalid.
NetworkManager: <info> Activation (ttyUSB2) failed.
NetworkManager: <info> (ttyUSB2): device state change: 9 -> 3 (reason 0)
NetworkManager: <info> (ttyUSB2): deactivating device (reason: 0).
[..]