Hello Laurent,
Glad it's working for you! The manual is also available for download, and is worth a read.
To get read/write access to the primary folders, you must log into Microsoft networking with the username "admin" and the current e-smith password.
When you create i-bays, you can configure them for "local" write access (instead of "admin") which allows anyone to write to the i-bay.
The next version of e-smith will also feature user-definable groups, as well as many other cool features. Have fun!
Best regards,
- Joe