1. How many files are you sharing? If it's over 2,000 then perhaps cut back. Some people have problems sharing too many files. In fact, for the time being, reduce it to below 50. Can experiment with re-adding more later.

2. Tip: Purge the Downloads Queue!

3. Do you use the iTunes sharing option? I'd suggest disabling this option. Go to LW's menu bar, Tools>Options>iTunes>Sharing. Well ... that's if it's possible for you to access it.

4. If you can't access your Options at all, then remove all files out of share & incomplete. Move your incomplete files somewhere else for the moment.