I was going mad fixing a bug in a very convoluted barcode printing feature in the equipment management system we’re developing. After a while I gave up – we must have triggered something deep within Rails or Ruby, and it wasn’t going to go away soon. The details are complicated and boring, and I ended up rewriting our barcode handling. As a side effect developed an extension for Ruby FPDF to support Gbarcode.
Please give it a try if you need barcode support in your PDFs and let me know what you want to improve and what fails horribly for you.