The problem is with untrained heli pilots. They don't seem to realise that flying towards another a/c will irritate the TCAS.
On numerous occasions, I have had the frantic palmtree pilots fly directly towards my a/c because they will obviously pass behind, but the TCAS doesn't like it and shows a TA symbol.
Luckily the TA audio and RA's are inhibited, but the TA symbol does catch your eye and I would go around if I did not have the chopper visual, because I don't trust the chopper students to stay clear.