[jQuery] attr ie bug

[jQuery] attr ie bug


hi
i got this code working in firefox but not in IE.
$("a[href]").each(function(){
        if ($(this).hasClass("ppt") || $(this).hasClass("pdf") || $
(this).hasClass("allegato") || $(this).hasClass("doc") || $
(this).hasClass("jpg") || $(this).hasClass("xls") || $
(this).hasClass("external") || $(this).hasClass("zip"))
         $(this).attr("target","_blank");
    });
am i doing anything wrong, is a ie bug o a jquery bug?
any idea?
thanx vitto