Some of you may have noticed that in the new Kazaa Lite when you double click an item it'll open in Winamp (or in whatever your computer handles that file type). To me this was very annoying and I couldn't figure out what was causing it until:
Go to Options> KL Extensions Options... and then go to Interface and un-check the third tickbox.
There you go! Now Kazaa Lite plays all your files like it did in prior versions!