[jQuery] Is this normal?

[jQuery] Is this normal?


This function give me a unexpected results in IE, FF and Opera:
var resizeFirstRow = function (t){
$("tbody tr:eq(1) td",t).each( function( k ) {
$(this).css("width",headers[k].width+"px");
alert( $(this).width() );
alert( $(this).css("width") );
});
}
where headers is a array with a width values: 80,90,250,80
and t is a div with a table element - i.e the parameter t is:
<div><table><tbody>.....</tbody><table><div>
in FF the result is
80, 80px
90, 90px
250, 250px
80, 80px
in IE
84, 80px
94, 90px
254, 250px
84, 80px
and the big problem in Opera (9.2 for windows)
129, 80px
129, 90px
129, 250px
129, 80px
In Opera the columns are not resized.
Any idea haw to resize a columns in Opera?