I have a problem with a Bag instance. When execute this code : initialize bag:= Bag new. bag add: 'Dario'. bag add: 'Dario'. bag add: 'Dario'. bag add: 'Dario'. voceA := Voce new. bag add: voceA. bag add: voceA. bag add: Voce new. ^bag Somtime this code answer aBag with two element: Dario-> 4 aVoce -> 3. Somtime this code answer aBag with three element: Dario-> 4 aVoce -> 2. aVoce-> 1. The Voce class implement the method = . It answer true. Any pointers would be greatly appreciated! Thanks! Dario