today i discovered why sometimes, some of my latex output contains tildes (~) in the dvi/pdf version. usually, if you use a tilde in a tex file, it is interpreted as a non-breakable space (except in special circumstances, such as verbatim environments or in `\url{…}`). but thanks to a “bugfix” to texi2dvi/texi2pdf, which is a wonderful tool as it runs (pdf)latex often enough together with bibtex, makeindex etc., tildes appearing in tex files are now shown as tildes in the dvi/pdf output. which is absolutely inacceptable behaviour.
anyway, i fixed my local installed version (`/usr/bin/texi2dvi`) by chaning the line `catcode_special=true` to `catcode_special=false`. a more sophisticated version would be nice, which only changes `catcode_special` for tex files (and not for texinfo files), but i don’t have time for that now.