Total Calculation Incorrect When Using Coupons

-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.3.3
-- PHP version -- : 5.4.41
-- Browser(s) name and version -- : Chrome Version 43.0.2357.124 (64-bit)

Hi there,

I am testing the Hikashop shopping cart before making our website live, and I noticed that the total calculation seems to be incorrect when we use a Hikashop coupon. Please see the attached screenshot for examples of receipts.

In one example, it seems the total should be $149.73 (when manually adding the subtotal, coupon, GST, and PST), but the total displays as $150.93 ($1.20 difference).

In another example, it seems the total should be $77.51 (when manually adding the subtotal, coupon, GST, and PST), but the total displays as $78.71 ($1.20 difference).

In the third example, it seems the total should be $121.84 (when manually adding the subtotal, coupon, GST, and PST), but the total displays as $122.89 ($1.05 difference).

I've also attached screenshots of my relevant configuration pages.

I can't figure out why the calculation is incorrect.

Please let me know how I can fix this and/or if you need more information from me.

Thank you!