add to cart (session variables) not working

[eluser]Davcon[/eluser]
Hi,

I wonder if anyone can help.

I have built a shopping cart using Codeigniter. I did not use the onboard shopping class cart - I wrote my own script.

Everything works fine except for one thing - for a very small number of people when they add an item to cart it says that the cart is empty. So, the items simply do not add.

Does anyone know what might be causing this? I'm stumped.


The way the cart works is using native PHP sessions. So, when somebody adds to the cart, it records their session id and inserts that, along with their item details onto a MySQL table.