I have a Nikon Coolpix S51 which is a little differnt than yours but I was having the same issue. The lens cover wouldn't close when turned off and it gave me a "lens error" and wouldn't let me take any pictures. I went on to all of these forums and nothing helped out. I decided that having it fixed would cost more than the actual camera and decided to fix the problem myself, while having no techinical experience and well knowing that if I messed it up more that I was just going to trash it.
I took the camera completely apart and found that the gears that moved the lens cover open/closed was not locked into place and debris was in between the gears. I simply used an air duster to remove the debris and made sure the gears were moving...