I noticed a weird bug in the LibraryJavaSound plug-in today, where if the source and listener have exactly the same position, the source is silent regardless of its intended volume. This is on my PC running Linux and 64-bit Sun Java (a combination which has a multitude of other problems), so I'll verify that this is happening on "normal" computers as well when I get home this evening (if anyone wants to test this for me, try playing a source from position 0,0,0 without moving the listener, and see if you hear anything).