Dmitriy thanks for your reply.
It's not that. The
Use windows (even for modern browsers) it's unchecked. The problem its more complicated and now I think the problem comes from my site. Its a custom CMS for Web Hosting (WHMCS) and the button code goes to the header.tpl file (necessarily). The tpl extension maybe its a problem too.
When I was click in the image on the Button Generator area works fine, but when I click on the site, it opens on a new tab. So, for that reason I believe its a problem comes from the site files.
Anyway... I have tried many thinks and nothing works. Maybe there is no way to fix this...
Thanks for your help anyway...