See screenshot.

There are some overlong URLs in the footnote area flowing over the right border.

Is there some chance for a forced line-break inside the URLs?

1. Bildschirmfoto 2011-05-02 um 15.32.25.png‎ 112.1 kB

Try adding a zero width breaking space,

{prince-text-replace: "/" "/\200B" }

Here are nice to know code points
Zero width space \200B (breaking)
Non breaking space \00a0
Non breaking hyphen \2011
Non breaking thin space \202F (with em-dash)

Jim Albright
Wycliffe Bible Translators