items not adding to cart/basket

I have a site www.patriciadawson.com. This was built using eCart 3 and 4.
This has worked fine for over two years, now when you go and add an iten to the basket, sometimes it will add the item, sometimes it will not, and displays the 'Empty basket' page.

This mainly seems to be happening in IE on a PC?

Any ideas as I am totally lost!

Thanks in advance

Lee

This post has been deleted.

my first though is that there is an issue with session management on the server see this post for details:
showpost.php?p=23826&postcount=2

thanks for that. The sessionTest.php test ok. Any other ideas?

can you send a copy of the ProductDetail.php page

file attached as requested.

try changing this code:

<?php

// WA eCart Redirect

if ($PDcart->redirStr != "")     {

  header("Location: ".$PDcart->redirStr);

}

?>

to:

<?php

// WA eCart Redirect

if ($PDcart->redirStr != "")     {

   session_commit();

  header("Location: ".$PDcart->redirStr);

}

?>

thanks for that, IE just stopped working so cannot test. just doing a full shutdown, did you manage to see the problem (not adding to cart)?
If so, could you tell me what this change has done?

Thanks so much for your help.

Yes, I did see the problem happen.

This code change will force the session information to be committed to the servers memory.

In some cases, the session changes are not committed to memory when the header() function is used to redirect the page. This change will force the session changes to be remembered by the server.