This is normal, comes on the lonestars too.. I forget its exact purpose, I think it's for stopping rattling, not sure.. but I called mesa for my father's lonestar special one time and they said it's normal and not to mess with it.
THere's a thread about this somewhere over at Harmony Central. If I remember correctly, Plat is right - it's supposed to keep everything buttoned up nice and tight so that things don't vibrate too much in there. Don't mess with it.