One question, are you knowing what you are doing? Removing ~/.kde, to reset the menu is like shooting bird with rockets! You destroy all your confutations. In LXDE you have luck, because it's component based and the applications have their own config dirs.
What version of LXPanel are you using? (open an terminal and type in "lxpanel -v" without quotes, and post the output here) What distribution are you using?
You can find very much informations about your menu related question in the forum.