You are using \multirow{3}{...} for this cell and therefore explicitly requesting three lines, but then you have enough text for four lines. Either change it to \multirow{4}{...} and add a \\ or change the column type to p{.3\framewidth}.
Note that AFAIK \multirow sets the official height of the content to be only the first line and the rest is then part of the depth.
See also the answers to the questions "Why doesn't \settoheight of \parbox work?" and "Measuring height of fixed-width text box" which explain how to measure the correct height for such boxes.
In response to the OP's comment:
You could define all three columns as p type columns and enter the right side content as one cell, like the others. You can use \newline as line break command:
\documentclass[a4paper,draft]{article}
\usepackage{calc}
\usepackage{graphicx}
\usepackage{tabularx,multirow}
\usepackage{geometry}
\geometry{hmargin=0cm}
\newlength\framewidth
\setlength{\framewidth}{\paperwidth}
\addtolength{\framewidth}{-3cm}
\begin{document}
\centering
\fbox{%
\begin{tabularx}{\framewidth}{p{.3\framewidth}p{.3\framewidth}p{.3\framewidth}}
\multirow{3}{0.30\framewidth}{%
\centering
%\includegraphics[width=0.2\textwidth]{Images/Logo}%
\rule{.2\textwidth}{1cm}
\vspace{0.1cm}\linebreak\sffamily\tiny
subtext\linebreak
more text} &%
\centering\large\textsc{Project name}\linebreak\textbf{Current document, more text, and even more text, still more text}
&%
{ a \newline b \newline c \newline } \\
\end{tabularx}%
}
\end{document}
I think the tabular environment might be not the best option in this case. Three minipages side by side would be better suited:
\documentclass[a4paper]{article}
\usepackage{graphicx}
\usepackage{tabularx}
\usepackage{calc}
\newlength\framewidth
\setlength{\framewidth}{\textwidth-4\tabcolsep-2\fboxsep}
\begin{document}
\centering
% Horizontal rule for comparison
\hrule\par\bigskip
\fbox{%
\begin{minipage}[t]{.333\framewidth}
\centering
\vspace*{0pt}
%\includegraphics[width=0.2\textwidth]{Images/Logo}%
\rule{.8\textwidth}{1cm}% graphic dummy
\\[.1cm]\sffamily\tiny
subtext\linebreak
more text
\end{minipage}%
\hspace{2\tabcolsep}%
\begin{minipage}[t]{.333\framewidth}
\centering\large\textsc{Project name}\\
\bfseries Current document, more text, and even more text,
still more text
\end{minipage}%
\hspace{2\tabcolsep}%
\begin{minipage}[t]{.333\framewidth}
a \\ b \\ c
\end{minipage}%
}
\end{document}
graphicxpackage with the [demo] option, and just use anything you'd like as a placeholder name of the image when including it. See the revision history to check what I have changed. – Martin Tapankov Feb 25 '11 at 12:41Xcolumns withtabularxdoesn't make much sense. You can just replace them (or at least the first two) withp{.333\framewidth}instead. – Martin Scharrer Feb 25 '11 at 12:48Xis calculating the column distance in andp{ }of course not. Use the calculations in my updated answer to compensate for that. – Martin Scharrer Feb 25 '11 at 14:36