I am trying to use the moderntimeline package for moderncv but pdflatex is giving me errors. All .sty files are stock. Here is a simple code that produces the error for me.
\documentclass{moderncv}
\usepackage{moderntimeline}
\moderncvtheme{classic}
\tlmaxdates{2007}{2012}
\firstname{Lorem}
\familyname{Ipsum}
\begin{document}
\tllabelcventry[magenta]{2002}{2003}{July--November 2002}{Scribus Student}{GNU School}{The Internet}{}{Tried Scribus for a short while}
\end{document}
The error from the log reads ! Package PGF Math Error: Unknown function 'ifthenelse'.
Here's what the PDF looks like:

\listfilesbefore\documentclass ...in your MWE and check thelogfile. Please add the list of used packages in your question. Your MWE runs on my MiKTeX 2.9 system without any errors ... – Kurt Dec 22 '12 at 18:09