Comment 2 for bug 396025

Some follow-up:
Looking at input and output files as text, it seems psnup doesn't write %%DocumentMedia and %%BoundingBox lines to the output. When I copy the lines
%%DocumentMedia: plain 595 842 0 () ()
%%BoundingBox: 0 0 595 842
from the input into the output file, everything shows correctly: correct papersize, no lost text.
(Why it should default to US-letter when both my /etc/papersize and en-GB locale are A4-centric is beyond me.)