I am experiencing weird issue on my Notebook running Ubuntu Gutsy. Often, I will loose wireless connection and network manager will attempt to reconnect, but in stead of properly reconnecting to wireless router it just hangs. Whats more weird is, after this, I am unable to start any X application with few exceptions.
I have reported the bug here . Many have reported similar problems and I am waiting for a fix. However temporary workaround seems to be, to run
$ network-admin --sm-diable
and reset the network connections. Also, you can try deleting the /tmp/.ICE-Unix directory and files.