Some of my cookies aren't tracking!

I recently started using cookies to track SID info for my CJ merchant. Unfortunately some of my SID fields in CJ reports are empty. The merchant I am promoting tracks both leads and sales so I have been able to test various situations and cannot seem to find out why this is happening. My site isn't indexed yet so I know it isn't sales from SEO.

This is the step by step process I use starting from the destination url in ppc campaign:

ex: http://www.mysite.com/landingpage?OVKEY=keyword

I use OVKEY for all of my campaigns that I have running for MSN, Google, and Yahoo because that is what Yahoo uses for tracking urls. I add GG and MSN to the {keyword} parameter to denote the difference between the three engines.

I then connect to my mysql database and exchange the keyword for its encrypted version so merchants cannot see this information. My mysql table has two columns, ovkey and sid.

Here is the php code I am using:

if (isset($_GET['OVKEY'])) { // Check to see if there is URL string OVKEY

$ovkey=$_GET['OVKEY'];

// Connect to the database
require_once ('mysql_connect.php');

// Make the query.
$query = "SELECT * FROM mytable WHERE ovkey='$ovkey'";
$result = @mysql_query ($query); // Run the query.
$row = mysql_fetch_array ($result, MYSQL_ASSOC); // Return a record if applicable

if ($row) { // Keyword code pulled from database.
setcookie("mycookie", $row['sid'], time()+31536000,"/","www.mysite.com");
}

// The next code is to get the keyword tracking for an advanced link since the cookie will not be available unless the page is refreshed or another link is clicked. The other links on the page go thru a php redirect.

if (!isset($_COOKIE['mycookie'])) {
$_COOKIE['mycookie'] = $row['sid'];
}
}
header('P3P: policyref="http://www.mysite.com/w3c/p3p.xml", CP="NOI CURa ADMa DEVa TAIa OUR BUS IND COM NAV INT"'); // Compact Privacy Policy

?>

I use this code to attached the keyword paramater to my advanced link:

I have already fixed two issues that I could figure out. The first has to do with not being able to access the cookie on the page where the cookie was first set. I added the following code to fix the problem:

if (!isset($_COOKIE['mycookie'])) {
$_COOKIE['mycookie'] = $row['sid'];
}

This fixed the problem and I was able to see the sid field filled in on the advanced link with the appropriate tracking code.

The second issue I resloved has to do with P3P compact policies. In Internet explorer I found out a cookie can be blocked if you do not have the appropriate policy that matches the user preference. I added a compact policy and my cookie sets even when the browser's cookie setting are set on high.

I have tested a bunch of scenarios in IE, Firefox, and Netscape and the SID tracking worked fine for me.

I am running out of options to why this is happening. If anyone has any ideas I would like to hear them. The only other thing I can think of is maybe the advanced link was clicked on before I fixed these problems. But, if anyone sees anything wrong with my code I would appreciate feedback.

Thanks,

Jeff