Quote Originally Posted by vivaraquel View Post

Obviously it's something to do with the weight. However, even the aus post site is quoting it correctly as a parcel under 250 gms. I am confused as to why it's doing this. My parcel weight ratios in the SHIPPING settings are set to 0:0. All the neccesary files are set from lbs to gms.

Any idea will be appreciated.
The fact that you've narrowed the problem down to being weight related has certainly helped heaps. What you have effectively done is proven that the AP module isn't at fault. The AP module is merely passing on the weights (number of parcels) that it is given from somewhere in the depths of the zencart core code.

I can appreciate that knowing this little fact probably doesn't help any <grin>

If it isn't the AP causing the problem, then the only other place where parcels are split into boxes is the code that deals with your maximum shipping weights, so that'd be the next place to start looking. You probably have your maximum shipping weight set to "20" (I think that is the default), so if you are weighing in grams you'll need to change this to 20000gms (20kgs).

Cheers
Rod