Default [Q] [ROM][CM 11] [ARC S] Problem with roaming

Hi. I didn't found this problem in other thread. I flashed the version of 20140122 of CM 11 on my Xperia Arc S. Everything appears perfect but I have a problem when I go out from Italy (Switzerland): though the roaming is disabled, automatically goes on internet and it consequently decreases phone credit. I established that it isn't a problem of the telephone operator, so it could be a problem of the phone. Without CM i didn't have any problem. What can I do?