Problem to call another user through Voxalot

[Cris77]

I have 2 Aladino Wifi (Samsung WIP-6000M H/W Version V.31 S/W V2.2.0).

One is in Italy connected to eu.voxalot.com and one in US connected to us.voxalot.com).
I am using the one in US to call thought Voipdiscount and other providers without any major problems.
Till a few weeks ago I was able to call the phone in Italy through Voxalot without using any intermediate providers.
A few weeks ago I could not connect to the phone in Italy anymore.

Each time I call or I am called the phone reset or I could not hear the other person or viceversa.

I wonder if something changed lately in voxalot that determined this problem and how I can fix it.

-Cris