PayPal error--customer can't check out

[DarkAngel]

fantasiesrealm.com/market
1.3.9h
PHP Version: 5.4.45 (Zend: 2.4.0)

I have a customer that is in a loop from step 2, step 3 then back to step 2 at checkout. Ihave gotten this error message from paypal concerning her order.

ALERT: PayPal Express Checkout Error (10426)
10426 Invalid Data - Item total is invalid.

I then checked her order and sure enough the sillly thing registers the total at $13.00 vs the actual price which is $13.01 -- how do I fix this. This has never happened before, ever, and she is the first one.

She is waiting to hear from me again to tell her she can try checking out again.

[lat9]

It would help if you could identify the values that are "in play" in that order:

The products' quantities and 4-decimal-place prices
The tax rate applied
Any currency conversions applied

Note also that there have been a bunch of rounding-related corrections that have been applied to the Zen Cart core over the last 6 years (1.3.9h was released in October 2010).

[DarkAngel]

It would help if you could identify the values that are "in play" in that order:

The products' quantities and 4-decimal-place prices
The tax rate applied
Any currency conversions applied

Note also that there have been a bunch of rounding-related corrections that have been applied to the Zen Cart core over the last 6 years (1.3.9h was released in October 2010).

Yes I know and have had trouble when trying the newer versions. Still working on that but I do not wish to lose everything in the process, which happens when I try it in a test store.

QTY items are 7 items total: x4 free items then, $1.63 -- $5.20 -- $6.18

Tax is factored into the pricing

Location: S. Africa

My shopping cart is tallying it up as 13.00 even instead of the 13.01. Never happened before either.

Well I just checked again and now it is registering 13.01 so maybe it fixed itself??? Anyway if you can give me an idea of what needs to be done then if it still won't work for her I can try your suggestions.

[lat9]

Software doesn't (normally) "fix itself", so there's something else going on.