You still have not registered your game. I hope it is a legal copy you have, you must register the game if you want any further help.Angus.
Registering your code was just to show us that you were legit and that you had a legal copy of the game. Now we can help you solve the issue.
Luca, it might be helpful if you posted your dxdiag.Here is how to do it: http://forum.shipsim.com/index.php/topic,23335.0.htmlI also found this topic, in which it appears to be an old problem with Steam versions:http://forum.shipsim.com/index.php/topic,28719.0.html#top
Good work finding that topic Salty. I did not find it although I was looking for some clue to what was causing Luca's problem.Angus.