[C320-list] Boom noise

[JPMESA at aol.com]

When reaching & broad reaching in light air I'm getting a funny clank  noise 
coming from the boom . It comes and goes sometimes taking several minutes  
before it makes the sound again. When the wind picks up (pressure) the  sound 
disappears.  It is not coming from the back of the boom  (Dutchman) I have bubble 
wrap back there to cover that problem. I also noticed  the boom moves a 
little bit at the mast connection. That makes some noise  in light air, but that's 
not it either. Any other ideas?  JOHN &  BOBBI Holokai 2
PS:I don't believe it's a big deal (structural), but it has become a  mission 
for me to figure it out!!