Problems with 3G

[Guest dbotti]

Hi, I Have an Omnia i900L VEHJ6 in Argentina and everything was fine but two days ago the 3G band had problems. The 3G icon is on the top but I can't receive or make calls and I can't connect to internet. When I change the band to 850/1900 everything seems to work perfectly (in G, H or E). I have made a hard reset and the problem continue. Movistar here in Argentina didn't know what happened. Any idea?

Regards.

Daniel