There appear to be bugs :).

Um, yeah, I mentioned as much. Last (non-code) paragraph from my previous post:

...the format of the struct definitions is always the same. And my subroutine takes this into account -- it fails horribly with comments in the code, but works just fine for the "live" code.

I originally had only one of the s/// operations, then was playing around with another -- now that you point out the combination of the two it's very obvious. Doh.