# Problem using diagbox in Beamer

I am trying to use diagbox in Beamer to create a north-east angled diagonal in a table cell using the tabular environment. It works in Beamer poster style but I can't get it to work for a standard Beamer presentation. So for example this code:

works in beamer poster but not in beamer. Am using MacTeX.

Does anyone know a fix for this?

\begin{tabular}{|c|c|c|}
\hline
& \cellcolor{red} \textcolor{white}{A} & \cellcolor{red} \textcolor{white}{D}\\
\hline
\cellcolor{red} \textcolor{white}{A} &  \diagbox[dir=NE,width=5em]{ {\tiny$$r((1,0),\omega (1,1),1,1)$$} }{ {\tiny $$(0,0,0,1)$$ } } & \diagbox[dir=NE,width=6em]{{\tiny$$r((1,0),\omega (1,0),1,0)$$} }{{\tiny $$(0,0,0,1)$$}}\\
\hline
\cellcolor{red}\textcolor{white}{D} & \diagbox[dir=NE,width=5em]{{\tiny$$r((1,0),\omega (0,1),0,1)$$} }{{\tiny (0,1/2,0,1/2)}}& \diagbox[dir=NE,width=6em]{{\tiny$$r((1,0),\omega(0,0),0,0)$$} }{{\tiny (0,1/2,0,1/2)}}\\
\hline
\end{tabular}


Beamer and beamerposter are different packages one loads xcolor itself the other one does not. I assume that you are loading the package xcolor with the table option (something like \usepackage[table]{xcolor}), when using beamerposter.
Beamer itself loads the xcolor package before that, which can cause trouble. So remove the \usepackage[table]{xcolor} line and add the documentclass option "tabel" which should look like \documentclass[table]{beamer}.
• maybe you can post an example from \documentclass till \end{document}. That would help finding a solution. Feb 25 '14 at 18:23