I had my shiny new 64-bit Ubuntu 8.10 up and running and then decided to do some arrangements on my menus and behold … I would right-click on the Ubuntu icon and select Edit Menus but nothing would happen. Even a trip to Preferences->Main Menu was unresponsive. Well, I know that the program that does menu editing in Gnome is called alacarte, so I decided to run alacarte from the command line and that is where I discovered the source of the problems. U see during setup, when u choose you language and country, Ubuntu setup uses them to decide your locale, so in my case my locale turned out to be en_NG (Nigerian English) and that was just not an acceptable locale to Python (the programming language in which alacarte is written). So how do you fix it? … simple, just set your locale to one of the mainstream (whoever decides that, I don´t know) ones, in my case, since we actually use British English.
Go to Settings.Adminstration.Language Support. In the Default Language section, choose English UK, or English US.
I suspect that French France, Spannish Spain etc would work for the other major languages.
With those settings, just log off and log back in (or better still just reboot) and your menu editing woes will be over.
For the curious, with my choice, my locale became en_GB (or is it en_UK?) which was an acceptable locale to Python.