I agree with Christophe and think that you are using stateful/stateless beans in an incorrect manner.
Stateless Beans (and their members) are not meant to be shared across clients. They should not save a state (in this case the counter variable).
For Stateful Beans it's ok to save the state (counter) which is bound to the client.
I suggest using JSF 2.0 and EJB 3.1. Live is so much easier with it