I don't want to argue - I simply don't see those entries on my system using Menu Editor. I know where they should be (right under the "System" tab) but they're not there to uncheck. Or do you use Alacarte?
But anyway, I'm using Hardy on this machine... on my sole Intrepid machine, I've already removed all such stuff (GNOME and Ubuntu docs), so I can't be sure what would have been possible. I simply know that as soon as you remove the package I stated, the entry will be gone. If you can uncheck them using Menu Editor in Intrepid, that's fine by me.