My website runs the latest version of Zen Cart (1.3.9h) and an unknown version of the Dual Pricing - Wholesale Pricing mod, although judging from the contents of v1.7a and v1.6, along with the date when the site underwent new administration (July), I suspect it is v1.6; ever since updating in August from 1.3.7 to the then-latest version 1.3.9e, we noticed that wholesale customers had been getting incorrect shipping charges!

Below is my zone-rate configuration:
Code:
Enable Zones Method
True

Calculation Method
Price

Tax Class
--none--

Tax Basis
Shipping

Sort Order
0

Skip Countries, use a comma separated list of the two character ISO country codes


Zone 1 Countries
US

Zone 1 Shipping Table
45:10,70:16,95:20,125:24,10000:24

Zone 1 Handling Fee
0

Handling Per Order or Per Box Zone 1 (when by weight)
Order

Zone 2 Countries
AU

Zone 2 Shipping Table
10000:54.5

Zone 2 Handling Fee
0

Handling Per Order or Per Box Zone 2 (when by weight)
Order

Zone 3 Countries
00

Zone 3 Shipping Table
10000:40

Zone 3 Handling Fee
0

Handling Per Order or Per Box Zone 3 (when by weight)
Order
The problem is that when a wholesale customer ships an order of more than $45 to the United States, he or she ought to receive a shipping charge of at least $16 but instead still receives a $10 shipping charge; this problem does not manifest itself for retail customers or for orders outside the United States (possibly because there is only one flat rate per zone).

Could someone tell me what about wholesale status may affect zone shipping rates, or at least how to tell which version of Dual Pricing I have so that I may properly upgrade to v1.7a to see whether that solves my problem?