I feel bad spending so much time on this situation. I understood my problem coming effectively from an out of gas issue.

What I didn't know was that the gas to be used was not taken by default from the constructor gas field. I now understand that the JavaScript function of the instance should be passed a `{from: account, gas: <gas to use>}` each and every time.

This is annoying considering that the remaining gas will be returned to the account caller.

Is there a way to set by default the gas to be sent in the same way we have the `eth.defaultAccount`?