NetworkManager fails to connect to wireless networks after kdm is restarted; seems dbus-related

[Peter Wu]

Binary package hint: network-manager

Since Kubuntu 11.04 Natty, NetworkManager fails to connect to wireless networks after a restart of kdm.
Restarting KDM can be done by running `sudo restart kdm` or by using SAK (Alt + SysRq + K).

It've noticed it first with a LiveCD and thought the problem was limited to it. Unfortunately, it doesn't, and appears on installation too.

To get NetworkManager connecting with a wireless network again, I tried (without luck):
- unloading the iwlagn driver
- restarting network-manager
- rfkill hardware switch
- rfkill software switch
- using "disable networks" checkbox in the applet

Suddenly, I got a strange feeling that dbus could have something to do with it, so I tried:
- logout from GUI
- switch to a console (Ctrl + Alt + F1) and login
- run: sudo stop dbus
- run: sudo rm -r /var/run/dbus/ (see also https://bugs.launchpad.net/ubuntu/+source/dbus/+bug/786221)
- run: sudo start dbus
- run: sudo restart network-manager
- switch back to GUI (Ctrl + Alt + F7) and login
- NetworkManager can connect to wireless networks again

In Kubuntu 10.10 Maverick, I had no issues with this.

[Iñaki Baz Castillo (ibc-aliax)]

I do confirm this bug. It has never happened before with any Kubuntu (or Debian) version. It just occurs after upgrading to 11.04 Natty.

I also reported this bug in #786882.

It's an annoying bug which makes a bit unusable my laptop.

[Thomas Hood (jdthood)]

@Lekensteyn: Is the bug reproducible in Ubuntu 12.04?

[Peter Wu (lekensteyn)]

I don't remember having this issue in Precise, I guess it can be closed.

[Thomas Hood (jdthood)]

Thanks for the update.