illegal units of measure with textblock

Question

I am 100 % sure this code worked within my presentation I held 2 years ago. I reopened it but I do get the error Illegal unit of measure (pt inserted)

{
\usebackgroundtemplate{

    \includegraphics[width=\paperwidth,height=\paperheight]{pictures/constraints_column_opak2.pdf}}

\begin{frame}
\LARGE
        \begin{textblock*}{\textwidth}(100,100)
                        \begin{itemize}
                        \item $\Delta p \propto \frac{1}{d^2}$  
                        \item Pore diffusion
                        \item Column blocking
                        \item Often very expensive

                        \end{itemize}       
        \end{textblock*}

\end{frame}
}

If I insert (100pt,100pt) everything works fine. Any ideas what might cause this error ?

Answer 1

Hmm, if that worked, it was probably by accident. The {textblock*} environment has always required absolute dimensions in its (100pt,100pt) argument, not the arguments relative to the \TPHorizModule and \TPVertModule which {textblock} takes.

(Note that textpos v1.8 was recently released, which had a few tweaks in this general area)