data roaming does not work in Argentina

Hi,

I switch to the simple choice plan because I was traveling to Argentina and I wanted to get access to data. But I have been here for almost a week and I cannot get data access. I was in Peru before coming to Argentina and it was working fine there. I have data roaming turned on. I get phone signal but no data. My phone is a samsung S2.

Any ideas?

Thanks,

Facundo.