Steps to reproduce:
* Create the following file tex.tex:
\documentclass[a4paper]{article}
\usepackage[russian]{babel}
\begin{document}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed ...
\end{document}
* pdflatex tex.tex
* okular tex.pdf
* Adjust zoom until you will see ugly "jumping" letters (i. e. one letter is up, and the following letter in the same word is down). For example, on my laptop with screen resolution 1600 x 900 pixels and physical size
214.8 cm x 381.9 cm zoom 100 % will go
What I see? Well, "jumping" letters. I see something like this: "LOrEm IpSum DOlOr SIT AmEt ...". See screenshot: http://picpaste.com/y-gh3PH69b.png .
What I expected to see? Normal beautiful text.
Including [russian]{babel} is mandatory to reproduce the bug. [english]{babel} will not go.
But the text itself need not to be in Russian. You don't need even \usepackage[...]{inputenc}.
latex tex.tex + okular tex.dvi - no bug.
latex tex.tex + dvipdfm tex.dvi + okular tex.pdf - no bug.
pdflatex tex.tex + okular tex.pdf - bug.
pdflatex tex.tex + evince tex.pdf - no bug.
pdflatex tex.tex + transfer this tex.pdf to Windows machine + open it with Adobe Reader on Windows - no bug.
TeXLive version info:
ii texlive-base 2012.20120611-5 all TeX Live: Essential programs and files
ii texlive-binaries 2012.20120628-4 amd64 Binaries for TeX Live
ii texlive-common 2012.20120611-5 all TeX Live: Base component
ii texlive-doc-base 2012.20120611-1 all TeX Live: TeX Live documentation
ii texlive-extra-utils 2012.20120611-2 all TeX Live: TeX auxiliary programs
ii texlive-font-utils 2012.20120611-2 all TeX Live: Graphics and font utilities
ii texlive-fonts-recommended 2012.20120611-5 all TeX Live: Recommended fonts
ii texlive-generic-extra 2012.20120611-2 all TeX Live: Extra generic packages
ii texlive-generic-recommended 2012.20120611-5 all TeX Live: Recommended generic packages
ii texlive-lang-cyrillic 2012.20120611-2 all TeX Live: Cyrillic
ii texlive-latex-base 2012.20120611-5 all TeX Live: Basic LaTeX packages
ii texlive-latex-extra 2012.20120611-2 all TeX Live: LaTeX supplementary packages
ii texlive-latex-recommended 2012.20120611-5 all TeX Live: LaTeX recommended packages
ii texlive-math-extra 2012.20120611-2 all TeX Live: Advanced math typesetting
ii texlive-metapost 2012.20120611-5 all TeX Live: MetaPost (and Metafont) drawing packages
ii texlive-pictures 2012.20120611-5 all TeX Live: Graphics packages and programs