Upgrading to Ubuntu 9.10 / Karmic broke my Wireless connection. I can connect to open networks but with hidden WPA2 networks the Network Manager Connect button is always disabled...
Looks like others are running into that bug too: https://bugs.launchpad.net/ubuntu/+source/network-manager-applet/+bug/446394. A fix has been committed in the Gnome repository, but there's no official installable package for it yet.
If you're impatient like me and need the fix now, here's how to build it:
Get the network manager applet source code from the Gnome GIT repository:
git clone git://git.gnome.org/network-manager-applet
The following version works for me:
e4cf9c6f1f95ce7d52d7cec435d95a5ddbf935a7 Tue Nov 17 00:58:14 2009 -0800
See the change log:
and the fix for the disabled Connect button bug:
If the build fails, you may have to install missing dev dependencies:
That list is what worked for me, and I already had many dev packages on my laptop. If you're still missing dependencies just try to guess what's missing from the build messages and install them until the build is happy.
sudo make install
The updated Network Manager applet works like a charm, I don't need to carry an Ethernet cable around anymore :) Bonus: the applet UI has improved a bit since the Karmic release.
Hope this helps (as a few folks at work have been running into that bug too and were asking me about it on Friday.)