I have done some searching and had seen a couple related posts to this problem. I ran into a problem this weekend booting from my internal MMC on my N800. I was installing some more problems, and then my main menu icons all disappeared?? I found some instructions as to a potential source of the problem with misstructured XML in the applications.menu file in /home/user/.osso/menus, however, my applications.menu file is blank. Is there a way to recreate this or find a backup somewhere else? Anyone know how to take care of this problem and why it might be happening? The last time I had this problem, I didn't have any way of bringing up xterm, so I had to re-flash my MMC.

Sorry, I meant "...installing some applications...", which in turn led to more problems!

After doing a lot of trial and error have come up with a solution. First you'll need some way of starting xterm. Fortunately, even though my applications were gone, I could still run a command through the statusbar-app, which allowed me to run xterm (osso-xterm). After that, I did the following:

1. sudo gainroot (if you do not have becomeroot installed, you may not be able to do this, but I am not sure if it absolutely necessary).

2. run this command: update-desktop-database /usr/share/applications/hildon/

3. then run: cp /etc/xdg/menus/applications.menu /home/user/.osso/menus/applications.menu

This seemed to work for me, so I hope it is of some help!