connect to mobile broadband twice, teardown connection and prohibit reconnect

I use the Vodafone UMTS stick for my internet connection and the nmcli command to control my network interfaces.

When establish a connection over UMTS via:
nmcli con up uuid <UUID of the connection>

All works fine if the mobile broadband connection is offline, but if a connection is already established, it gets disconnected.
When this happen it is not possible to reconnect. Neither over the nmcli command, nor the applet. Also a reboot of the computer does not help. Any reconnect attempt fail.
The weird thing is the applet show the the "Vodafone UMTS" entry in gray under mobile broadband and white in another section of the context menu. The command "nmcli con status" reports only my lan connection.

The only possibility to resolve this bug is to replug the usb stick. After this you can connect to the mobile broadband again.

Calling the "nmcli con up" command twice with my lan connection is no problem. The problem only occur with the mobile broadband.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: network-manager 0.9.4.0-0ubuntu4.1
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic 3.2.30
Uname: Linux 3.2.0-32-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.0.1-0ubuntu14
Architecture: amd64
Date: Sat Nov 10 17:19:24 2012
IfupdownConfig:
 auto lo
 iface lo inet loopback
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120823.1)
IpRoute:
 default dev usb0 proto static
 169.254.0.0/16 dev eth0 scope link metric 1000
 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.33 metric 1
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=false
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
mtime.conffile..etc.NetworkManager.NetworkManager.conf: 2012-10-31T17:45:10.567406
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 Winkel#Oder_HofO a6c81580-212d-4807-95e1-6e76906c6cdd 802-11-wireless 0 never yes no /org/freedesktop/NetworkManager/Settings/2
 Wired connection 1 9b60a295-d9f5-4ef5-8f90-0f29c7d13b56 802-3-ethernet 1352564326 Sa 10 Nov 2012 17:18:46 CET yes no /org/freedesktop/NetworkManager/Settings/1
 Vodafone UMTS 3233f410-9899-41d1-a108-19e90b9d604e gsm 1352564326 Sa 10 Nov 2012 17:18:46 CET no no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 usb0 gsm connected /org/freedesktop/NetworkManager/Devices/7
 eth0 802-3-ethernet connected /org/freedesktop/NetworkManager/Devices/2
 wlan0 802-11-wireless unavailable /org/freedesktop/NetworkManager/Devices/1
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.4.0 connected enabled enabled disabled enabled enabled