[PS3] Worms Ultimate Mayhem Online Problem

[The_Legend]

Hello guys, I have a problem with the online capabilities of Ultimate Mayhem Worms (PS3).
When I start a game and I will end my turn, the game stops for a while, as if it is charging, and Suddenly comes a screen with "The session is No Longer Available", I'm back in the main menu.
That Occurs only recall this problem when i end my turn. The problem Occurs even if we are more than 2 players, always after I finish the round.
Does anyone know why this problem? thanks
sorry for my English is not my native language