Hi, mate. I'm from Argentina as well.

As far as I know, the reason why S&W weapons can't be imported into our country right now is a ban impossed after a DoJ investigation of offenses against the Foreign Corrupt Practices Act.

Several executives from different companies were indicted, including S&W's VP Amaro Goncalves (who was arrested in Las Vegas in January 2010).

If I'm not mistaken, the ban expires in a few months.

Here's a US Department of Justice press release about the indictments and arrests (in Spanish): Departamento de Justicia