So,
I have written to Italian support of DLink and i'm waiting for reply. Actually support's processing my case.
It's possible that app DLink Lite uses the so called "value add-services" of telephone providers.
Value-added services, also called "premium" or "content", are services that can be provided by telephone provider or even by proprietary content companies, via SMS, MMS or via fixed-line (WEB) or mobile (WAP) that you can activate, receive and / or enjoy on your Phone, Tablet or PC.
These are services such as logos, ringtones, horoscopes, weather, news, videos, wallpapers and (more junk stuff)...
This morning I have called my telephone provider and I have enabled, at the moment, these services... So I have received the push notification when my camera has readed a movement this afternoon.
I dont know that it's the solution, I'm monitoring the situation in the next days.
I wait the reply of DLink support.
I update you
Thanks for attention
Daniele