You can easily go back to using LW 4 if you think it's better than LW 5

LW basic users can download here: Lime Wire » Download Out-Of-Date Installers

And Pro users have a link on the left side of their Pro download page - 'Get LimeWire Classic'.

Are you downloading torrents - using another site for the search & then opening the torrent with LW? LW's not a good torrent client. It doesn't keep track of share ratio, there's no way of choosing which files you want to download from within a torrent & there seem to be issues with continuing seeding torrents after the file's downloaded. I don't use private trackers but I've heard that LW's banned on some private trackers.
You're better off using a dedicated torrent client - the 2 most popluar are
Vuze and uTorrent.