[texhax] could someone give me an explanation as to why fontsize fails with an overfull box

[Carlos]

I was just having the following:


\documentclass{article}
%\documentclass[14pt]{extarticle}

%\usepackage{MinionPro}
\usepackage{mathptmx}
%\usepackage{libertine}
%\usepackage{fontspec}

%\setmainfont{MinionPro}

\setlength{\parindent}{9.94pt} 

\showoutput
\begin{document}

%\fontsize{14.09}{14}\selectfont
\fontsize{14.0908}{17}\selectfont
%\fontsize{16.09}{17}\selectfont

The reason is that upon restarting the computer, there are also other programs
that start running on the background, among them Antivirus programs and
whatever other programs Windows deems necessary for the functionality of
the system.

\end{document}




Unfortunately I couldn't get past the 14.0908 for
the font size when having a math font for example
or a 16.09 when having anything else, before the
textwidth for the document got thrown off.

Going by the TeXbook it says that `\rightkip` glue
is taken into consideration when badness and
demerits are computed, but I don't see any
badnessess here. 

By looking at the output no penalty comes after
the first rightskip either, so I'm at a loss here.

If anyone can clarify it for me, I'll appreciate
it. 

Thanks
Carlos