PHP to XLS Security Alert issue

["admin" <admin@xxxxxxxxxxxxxxxxxxx>]

I am exporting to a XLS file and the file does export, but when I open the
file Microsoft is giving a Excel Security Notice.

I am sure there is something in the header that is missing or causing this
problem.

 

header("Pragma: public");

header("Expires: 0");

header("Cache-Control: must-revalidate, post-check=0, pre-check=0");

header("Content-Type: application/force-download");

header("Content-Type: application/octet-stream");

header("Content-Type: application/download");

header("Content-Disposition: attachment;filename=list.xls");

header("Content-Transfer-Encoding: binary ");

 

I use pack() to write the labels, Numbers, data. If that could be the
culprit.

  echo pack("sssss", 0x203, 14, $Row, $Col, 0x0);

  echo pack("d", $Value);

 

I am running 5.2 on PHP and opening the document with 2010 Office on
Windows.