I've taken over the module (with Sami's permission), fixed the bug, and uploaded Business-ISSN-0.91.

The code is fully tested now, but if you find any more problems, please post them to RT as you did with this report.

Curiously, the ISSN code was derived from Business::ISBN, the second module I ever wrote. Looking at the code was going back in the time to see many of the worst practices I used to have, so updating the module gave me a chance to undo all of that and make amends. :)

Good luck :)