Network Manager Applet menu freezes and does not respond

Certain sources (notably Elementary Desktop's PPA) have a version of network-manager-gnome which is newer than the one in the canonical maverick repository. A fix has been issued for Natty, but is not in the Maverick repos yet. So Ubuntu sees the newer version in elementary-desktop, uses that instead of the canonical one and, hence, the bug.

The solution is to roll back the version of network-manager-gnome to the 0.8.1+git.20100809t190028.290dc70-0ubuntu3 from 0.8.2+git.20101123t161608.f143e76-0ubuntu1

This can be done from synaptic by searching for network-manager-gnome and then clicking 'force version' in the package menu and selecting the 0.8.1 version.