Recently I installed Slackware 13.37 on the computer of one of my colleagues. He had problem with displaying certain pdf files: The fonts for regular text were rendered boldface in Evince and Okular (but xpdf rendered it fine).
I made a google search and found the following page, where a Slackware user describes a fix:
To sum it up: The Nimbus font file n021004l.pfb needs to be updated. I applied the solution suggested on that page and it worked. This file appears in two places in Slackware packages:
I did the replacement in the /usr/share/fonts/Type1/ directory only, so I suppose ghostscript-fonts-std-8.11-noarch-1 is the responsible package. As far as I could find out it has been added in Slackware 12.0 and hasn't been updated since. Maybe it's time for an update?