updating menus seems to be ok - from ControlCenter, or doing it from console as you described. I can see all menu items on the list in menudrake programm, but it's not on the real menu.
I don't have most of menu items (what is left is just favourities, last opened docs and few others, probably this is from 'user' menu). Also I don't have ANY ITEMS at kde control center (just empty window with no items like font, color settings or anything else).
After reboot my desktop returned (?). Now I'm really confused. Is there no other options then reinstalling? :(
Maybe I should check my / partition for errors? How to do this? (both / and /home are ext3)