I have a table like this:
\begin{table}
\centering
\begin{center}
\begin{tabular}{c|c|c|c}
Data set & Image size & Hole size (pix) & Total time\\
\hline
Mailbox & 459 $\times$ 489 & 30171 & 1m5s \\
Electric boxes & 688 $\times$ 478 & 45434 & 2m19s\\
Trashcan & 572 $\times$ 517 & 42734 & 1m59s\\
Air conditioners & 400 $\times$ 496 & 13709 & 23s
\end{tabular}
\end{center}
\caption{A summary of the data sets shown throughout this paper.}
\label{tab:Timing}
\end{table}

The problem is that the caption is only about 1 word wide (and centered), so it takes up about 10 lines. Why would this caption not behave like a normal figure caption and simply occur page-width?
Here is a minimal working example (you need this style: daviddoria.com/Uploads/acmtog.cls):
\documentclass{acmtog}
\pdfminorversion=5
\begin{document}
\begin{table}
\centering
\begin{center}
\begin{tabular}{c|c|c|c}
Data set & Image size & Hole size (pix) & Total time\\
\hline
Mailbox & 459 $\times$ 489 & 30171 & 1m5s \\
Electric boxes & 688 $\times$ 478 & 45434 & 2m19s\\
Trashcan & 572 $\times$ 517 & 42734 & 1m59s\\
Air conditioners & 400 $\times$ 496 & 13709 & 23s
\end{tabular}
\end{center}
\caption{A summary of the data sets shown throughout this paper.}
\label{tab:Timing}
\end{table}
\end{document}
articledocument, for example, does not reproduce the behaviour. – Jake Apr 24 '12 at 15:49\centeringinside floats likefigureandtableis sufficient -- don't use thecenterenvironment in addition (or instead). See http://tex.stackexchange.com/questions/2651/should-i-use-center-or-centering-for-figures for details. – lockstep Apr 24 '12 at 16:02