Google Checkout issue

Hi 1.3.4 is still my favorite one to use but I noticed on orders going threw Google Checkout that the shipping does not pass over and then when you go to Google Merchant to see orders there is an area to charge what looks like a shipping dollar amount but is 3 to 4 dollars higher. For example the last order was 12.99 for item and 12.92 to ship, the 12.99 passes over and there is a doller amount that does pass but this one is 16.20 instead of 12.92.