I spend my days hopping between VPN connections in Ubuntu 10.10 and this is becoming severely annoying. What happens is that every once in a while - typically several times a day - when I click on the networking icon in the top bar, the nm-applet's VPN Connections flyout menu is gone. (Said menu item is still there, it just doesn't have a submenu or do anything when clicked.) Every time I killall nm-applet and start it again, which usually brings the menu back.
Has anybody here experienced this and been able to fix it?
This started to happen to me when I added the Nautilus Elementary PPA to my repo list. The version of network-manager-gnome available in that PPA is newer then the Canonical version and has some bugs in it that apparently crash the applet (causing the VPN menu to dissapear). You can check to see where your version of network-manager-gnome is coming from by opening synaptic and searching for network-manager-gnome. As of today, the latest Canonical version is 0.8.4~git.20110318t152954.9c4c9a0-0ubuntu1 and the maintainer of the package should be the Ubuntu Core Developers.
If you notice that your version of network-manager-gnome is not coming from the Canonical, select network-manager-gnome in synaptic and then select 'force version' from the package menu. This will prompt you to select the version you want to force, select 0.8.4~git.20110318t152954.9c4c9a0-0ubuntu1.