Much of BitTorrent traffic is getting classified into the Default bucket.
Because BitTorrent traffic is always changing, to classify this traffic you may need the newer classification code. The classification updates usually comes as a plug-in. Please make sure you have the lastest plugin loaded on the PacketShaper.
After installing the plug-in, you will need to delete the existing BitTorrent traffic class and then manually recreate a new class, or allow auto-discovery to create the class automatically. The new class will then classify BitTorrent traffic correctly.