Wholesale shipping incorrect under Dual Pricing

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:```
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

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?

I went ahead and updated the dual-pricing mod to the latest version, using WinMerge extensively to ensure that it was correct, but I still get the problem that wholesale customers always get the lowest shipping rate for each zone, regardless of how much their orders cost.

I am the person who maintains the website that kcarl was complaining about, and I discovered that the problem lies with the Dual Pricing mod not converting the text format that wholesale prices are stored in (so multiple prices may be stored and then extracted depending on which type of wholesale customer is needed) into floating-point decimals early enough, so that although wholesale customers don't end up getting items for free, the sub-total before shipping charges are applied does appear to be $0, and that is why wholesale customers always got the lowest shipping cost in their zones; I intend to update the mod accordingly and release a new version.