If you download your invoice in CSV format this notation appears near the top.

Note: The line item total may not match the invoice total because of rounding the Final Value Fees. This is for display purposes only. The exact amount is used to calculate the total balance. To correct this, we have included a Rounding Adjustment amount. See http://pages.ebay.com.au/help/account/rounding-account-balance.html for more information.

And the final entry on the page is a rounding adjustment which can be zero but is usually plus or minus one to two cents.

I did try the link but it tkes me to a Viewing your account page with no specific information about rounding.