Thanks Polonus and cheater for reply.
I was joomla 1.5x and my site was infect ( detect for avast) and I had my site in a hosting.
I install new joomla 3.0 in a new site , new site clear , in a new hosting , diferent to fist , only use same link www.famg.org.ar .

I think avast is continuous with the old register , ( the old site joo1,5) because my new site have 1 month and the avast block more the 2 months.

My new site only contains news records , none of the older site.

Do you have any solution?? I have another link that linking same site and isn´t block ( www.famg.com.ar)

Thanks Mys friends ,and Im sorry for my poor english :-[