comgt fails when USB modem is dialed in

[Rolf Leggewie]

$ lsusb -d 12d1:1003
Bus 001 Device 067: ID 12d1:1003 Huawei Technologies Co., Ltd. E220 HSDPA Modem / E270 HSDPA/HSUPA Modem

comgt package 0.32-2 on lucid. When I am dialed in via the USB stick (network-manager), I can no longer measure the signal strength.

$ sudo comgt -d /dev/ttyUSB1
 ***SIM ERROR***
Check device port configuration.
Check SIM is inserted
Test SIM in a mobile phone?

This works when there is no connection.

$ sudo comgt -d /dev/ttyUSB0
SIM ready
Waiting for Registration..(120 sec max)
Registered on Home network: "SMART",2
Signal Quality: 17,99
$ sudo comgt -d /dev/ttyUSB1
SIM ready
Waiting for Registration..(120 sec max)
Registered on Home network: "SMART",2
Signal Quality: 14,99

But after this I have to unplug and replug the device before I can use it again with network-manager. Not sure if this is a kernel bug, one in comgt or network-manager. The comgt developer explicitly confirms "This means for example you can have an active PPP connection on /dev/ttyUSB0 (or/dev/noz0) and still get signal stength reports." (http://www.pharscape.org/forum/index.php?topic=15.0)