Check you have enough free space, on the drive you have incomplete folder
on. If less than 3gig, sometimes this can cause probs.
Go, Start/My Computer/Veiw/Choose Details,& tick, free space.
Could also be down to fake files, Check this link.
http://www.gnutellaforums.com/download-upload-problems/63993-fake-files-search-results.html
Peace.