pdftk fails on valid pdf 1.5

Pdftk fails on some valid (large) pdf 1.5 files: http://tex.stackexchange.com/questions/95973/is-pdftex-1-40-13-outputting-malformed-pdfs . I am unfortunately unable to construct a small example. I will either attach the smallest example I have or, if that's impossible, post a download link.

Pdftk seems to be using its own out of date version of a library called iText. The situation with iText seems complicated, with various changes of license and as many as three forks. There is Lowagie's AGPL version, a debian/ubuntu package called libitext-java (which seems to be on version 2.1.7, making it either a fork or an extremely out of date version of Lowagie's), and one called itext-paulo which seems to be maintained internally as part of pdftk. The bug referred to in this report does not occur with recent versions of Lowagie's iText: http://sourceforge.net/mailarchive/forum.php?thread_name=1359559246.96119.YahooMailNeo%40web160501.mail.bf1.yahoo.com&forum_name=itext-questions