help with google checkout shipping?

ive been playing around with the ZC admin page settings for GC as well as the account settings in the GC admin settings and i cant get the shipping rates to show the proper prices.

i.e. when using GC on my website a 6-7 ounce package shows a shipping cost of ~12$. when calculating with usps website the actual shipping cost is ~18$. all shipping on the website is calculated by weight. i can find general instructions but nothing that goes into any kind of detail for getting setup.

ive also tried adding priority mail shipping through the GC admin settings but cant get it to show up. ive got some unwanted shipping methods to go away but cant get what i want to show up. where should i be trying to add/remove the shipping methods i want and how do i go about doing it? i cant seem to get this figured out. :(

website is my username with a .com at the end

anyone? :huh:

im using 1.3.9h and have tried everything i know to do. ive played around in the shop admin page with gc carrier calculated and merchant calculated. ive also tried the shipping generator. it shows the correct methods i want to use but copying and pasting to the shipping_methods.php seems to have no effect. gc carrier shows the wrong rates but is better than the 1$ shipping that shows up for merchant calculated. in google checkout merchant area ive added priority shipping as a carrier calculated choice but it doesnt show up when trying to checkout. as i stated in the first post express mail shows up as a lower cost than what it actually is. ive been searching for the past few days and can not find any explanation. :frusty: