Brief We have updated the script usps_v3.php to calculate correct prices.
Description When you specify how many items should fit in one package in Products > Top > Edit Product > 'Stock & Shipping' tab > 'Number of Packages' field the shipping prices were calculated incorrectly. For example, you could put "0.33" value in 'Number of Packages' field to fit 3 products in one package but instead on checkout the price was calculated for three packages.
Further, extract the file into the 'shipping' folder of your shop replacing an existing one. Do not forget to make a backup copy of the current file in case something goes wrong.