# Inconsistent margins using columns in beamer

Compare the two slides generated by the following code.

\documentclass[t]{beamer}
\usepackage{lipsum}
\begin{document}
\begin{frame}
\lipsum
\end{frame}
\begin{frame}
\begin{columns}[T]
\begin{column}{0.5\textwidth}
\lipsum
\end{column}
\begin{column}{0.5\textwidth}
\lipsum
\end{column}
\end{columns}
\end{frame}
\end{document}


Notice how, in two-column mode, the side-margins are smaller, and the top margin is larger. This makes the layout on my slides inconsistent when I mix a two-column and one-column layout, particularly if I do so on the same slide.

How do I get LaTeX to stop messing with margins in two-column mode?

Thanks, -Willard.

P.S.: In case someone else has the same issue: In two-column mode, if I had an image in one column, then placing a theorem in the other column would move the image. I traced this issue to

\setbeamercolor{structure}{...}


which apparently does more than just colour things. To change colors, use

\usecolortheme[...]{structure}