I have noticed another issue with this plugin which has to do with the pricing display.

If your store is setup to show prices with VAT (tax) included the plugin will display the saving incorrectly:

Retail Price: R3,990.00
You save: R526.32 (15%)
Our Price: R3,390.00

The store is setup to add a standard 14% VAT to all prices and the 526.32 is the saving excluding the 14% VAT.

This should read:

Retail Price: R3,990.00
You save: R600.00 (15%)
Our Price: R3,390.00

Anybody else having the same issue?