I'm using Avast Home Addition which is freeware. The great thing about Avast is it has P2P Shielding and scans Kazza Lite Downloads. Avast is set up to work with Kazza, Kazza Lite, Direct Connect, Direct Connect ++, Limeware, Bearshare, imesh. WinMx and Bit Torrent.
Check it out. Works great.