Cart not adding mutiple items to shipping

[pjuk]

I have my cart working and it works fine if only one product is ordered.

I have gone through all my products and tested them and they work fine.

But if i add another product on it seems to charge what its like for the shipping.

This is an example of one of my products.

Price 5.99 and shipping and handling is 4.99 and it comes up in the cart £10.98 like it should

Now if i add another product to it

This product is priced at 4.99 shipping and handling is 3.99 and it comes up in the cart £8.98 like it should

Now add to two products together in the cart and it come out as

£5.99
£4.99

Shipping £11.49 The shipping should be £8.98
Total £22.47

Now if i add another one again the ist one i used
Price 5.99 and shipping and handling is 4.99 and it comes up in the cart £10.98 like it should

It now comes out as

11.98
4.99

Shipping £ 5.99 The shipping should be £13.97 A huge loss to me of £7.98
Total £22.96

What is up with the shipping