Problems with accentuation in .load

The site is all right, database, files and meta everything in utf-8, but when I use

$("#aviso").load("inc/aviso.php");},1000);

It results in these characters , when I access the warning.php file it is with the accents all right.

I'm using the default utf-8 of the beginning, I do not know what else to do.

I even used

header ( "Content-Type: text/html; charset=utf-8" ) ;

mysql_query ( "SET NAMES 'utf8'" ) ;

mysql_query ( "SET character_set_connection=utf8" ) ;

mysql_query ( "SET character_set_client=utf8" ) ;

mysql_query ( "SET character_set_results=utf8" ) ;

But I did not succeed.