Select field in conditional group error

Hi,
First of all, thanks for your plugin which fit well for our needs.

However, we noticed an issue with one of our forms :

We make appear a select field to choose a federal state when the USA country is selected in a previous select field.
Everything works well except when someone selects USA country and then selects a federal state (e.g. California), but decides to finally change the country.

Actually, an email is sent to a specific recipient according to the country (or the state for USA) selected. But in the case detailed below, an email is sent to the corresponding US state recipient while USA has been unselected.

I have the impression that the conditional fiel is kept in memory when is selected and then unselected.

Is it a normal behavior or a plugin little bug ?

Thanks for your help.

The page I need help with: [log in to see the link]