Changing Weight from Pounds to Kilos

[artycles]

I'm in Australia, using 1.3.8 version. I've upgraded my AustPost thanks to Rod's help. Now have changed my lbs to grams.
Here's the current problem:

I've gone through and changed all the lbs to grams (using the developers tool kit I found them all eventually) and on the Austpost module also changed from Kgs to grams that I'm using. In testing it, the items in the shopping cart add correctly to 44grams but on the checkout the postage is calculating it way to much, I'm wondering what I've missed. Any ideas?

Ooooh I'm now thinking I should have made everying kgs and worked out every thing based on a 0.0kg...
I'll try that while I'm waiting to see if there was anything else.