Export / Import Extension - exported barcodes incorrect

Good day,

I am using Opencart 1.5.6.4 and the latest version of the Export/Import tool by Jneuhoff.

The problem I am having is that all my Comic books (Ironically, that's the only category this is happening with), are exporting with the incorrect barcode. Specifically the last 2 digits of their barcode are all being altered to "00" in the exported file.

I have attached a screenshot that should better show the problem.

Please can someone help me resolve this?