Yes you must enter your Samba details in wrapper app (My Apps - Wrapper).
Try reinstalling the wrapper.
* How to reinstall or uninstall wrapper? Using firmware 1.0.5 or later go My Apps - Wrapper and select either 'use wrapper player' or 'use Kodi player'. Toggling to 'use Kodi player', exiting wrapper app, then running wrapper app again and selecting 'use wrapper player' will reinstall wrapper.
An alternative way to access Samba shares which might work better for you is detailed in this thread: http://www.futeko.com/newforum/index.php?topic=813.0