Shipping making figures up

Selling Nitron Shock absorbers - http://www.nitron.co.uk/shop - shipping to the uk is fine as its a flat rate and I have that defined under flat rate box. we ship to 4 zones which I have defined using ISO codes. We basicly sell 3 types of shock and it is very unlikely that a customer will buy more than one item from us. The race and track shock weigh more than the sport so we pay different shipping rates.
To simplify I have product A set to weigh 50kg (its less than that but it was an easy number to remember) with products B&C to weigh 100kg then set the shipping rates up for the 4 zones. IE 50:price, 100:price and based calculation on weight.
When I come to estimate shipping or order the prices for shipping to X country bears no relation to what I want it to be
screen shot here http://homepage.ntlworld.com/deviate/shipping.jpg
any idea as to what I have done wrong.
I thought I was doing so well up to this point

I should mention this is a UK site shipping worldwide

TIA
Kev Kindred

as it wont let me edit it - I sorted it and it was all down to user (me) stupidity

Thanks for the update ... glad you got it sorted out ...