Hi Cristina,

Many smartphones and tablets (most notably Apple iPhones and iPads) do not support the Flash technology which is used in some of the Website X5 photo galleries.

However, you can greatly increase compatibility by switching to an alternative Javascript HTML5 gallery.

You can do this by editing the setting of the 'Gallery Type' drop-down menu, located on the 'Style' tab of the Gallery Object properties.  Press the F1 key whilst in that screen for help related specifically to the choices available.

Once you've made the changes, upload afresh to your webserver to test.

Hope that helps...

Paul