Using loop to add multiple items

Hi

I am using the add to cart code to add some multiple products into the cart. I have basically created a few arrays holding the product details required and amusing a while loop (I tried originally a for loop but that wouldn't work either) to loop through and enter each product before redirecting to the basket. Every time I go through to the basket it is empty but if I use debugging code and see what is happening through the for loop but add an exit before the redirect the products are in the basket. I can't for the life of me see why this would be ... any ideas? I am attaching the code block - as you can see I am doing a fair few things apart from the add to basket - these are all working fine.