First of all, here is a code to compile :
\documentclass[11pt,a4paper]{article}
\usepackage[latin1]{inputenc}
\usepackage{palatino} % for font
\usepackage{fancyhdr} % for header+footers
\usepackage{graphicx} % for plots/pictures
\usepackage{amssymb}
\usepackage{mathrsfs}
\usepackage{amsmath}
\usepackage[inner=3.5cm,outer=3cm,top=2cm,bottom=2.5cm,includeheadfoot]{geometry}
\pagestyle{fancy}
\lhead{Test Test Test}
\rhead{Fiche Archive}
\fancyfoot[C]{}
\fancyfoot[L]{\footnotesize{\copyright \hspace{0.1cm} Rien Rien Rien}}
\begin{document}
\begin{center}
{ \Large {\bf Stage }}
\end{center}
\vspace{0.5cm}
\hrule
\vspace{0.15cm}
\noindent$\bullet$ {\sc Identité de l'étudiant, Dddddd}
\vspace{0.15cm}
\hrule
\vspace{0.4cm}
\noindent{\bf NOM :} Nom
\noindent{\bf Pr\'enom :} Prénom
\noindent{\bf Filière :} ddqfqsf
\noindent{\bf Année Universitaire :} 2012-2013
\noindent{\bf Mail :} dfsdgsg
\vspace{0.5cm}
\end{document}
If you have a look at the resulting pdf file with Adobe Reader, you will probably see distortions in some letters the "T" and "D" but they may disappear while zooming.
I've been told this is an error by Adobe Reader which doesn't round correctly some pixels and leads to that scale effect.
But I would like to know if that is the only reason and if it could be avoided by setting parameters such as encoding type (latin, uft8), geometry or anything else

\scand\bfhave been deprecated commands in latex for 20 years, but you'd get the same fonts if you used the standard commands such as\bfseriesand\scshape– David Carlisle Sep 08 '13 at 20:02\usepackage[T1]{fontenc}(desirable, eg, to get hyphenation of words containing accents, as in French language). Because Computer Modern has no T1 encoding, you will get CM-Super which has similar problems with hinting. Latin modern (\usepackage{lmodern}) is generally superior to CM-Super, but still has hinting issues. – Lev Bishop Sep 08 '13 at 20:31\usepackage{ae}, although it is not without problems (eg, cutting and pasting accented text out of the PDF behaves strangely). – Lev Bishop Sep 08 '13 at 20:37