Have you had a look through your shared folder (tools > options > sharing) to check exactly what's there? If there are files that you don't recognise & haven't downloaded (providing nobody else has access to your LW & could've been downloading without you knowing), I'd recommend a visit to Norbiesworld.
If you go to the site, register & follow the directions for free computer help then Norbie will be able to check out your computer & tell you if you've got any uninvited guests onboard