I had a look at http://www.vitalweb.com.br/vital01/couch and the error it is showing is
Desculpe, Encontramos um erro interno no Servidor 500
Por favor informe na Ã¡rea de contato
Por favor volte para a pagina inicial
That is the web server's internal error 500.
Many reasons why this can happen (faulty .htaccess for example), but I don't think that Couch is the culprit here.
Maybe you could PM me your FTP username/password and I can dig further.