beamer: frame without decorations, with custom margin

I use \begin{frame}[plain] to have a frame without decorations. The content (inside columns environment) seems to horizontally still respecting the old margins (with Warsaw, gap on the left), although vertically, the whole space is taken as it should be. Beamer manual says that plain only suppresses decorations, but does not mention it changing geometry.

Is there a straightforward way to have empty frame, with some user-defined margins?

EDIT: this is what I get with the following; text on the second slide is not left.

\documentclass{beamer}
\usetheme{Berkeley}
\begin{document}
\section{foo}
\begin{frame}[t]
Text
\end{frame}
\begin{frame}[plain,t]
Text
\end{frame}
\end{document}


EDIT 2:

The solutions suggested by @MarcoDaniel does not restore the margin correctly unfortunately (without \restoregeometry, the slide decoration starts on the left correctly, but the block goes over it just like on the screenshot). Enclosing the change in \bgroup...\egroup does not help:

-

One way to do this is to use the changemargin environment from UK List of TeX FAQ:

\documentclass{beamer}
\usetheme{Berkeley}

\newenvironment{changemargin}[2]{%
\begin{list}{}{%
\setlength{\topsep}{0pt}%
\setlength{\leftmargin}{#1}%
\setlength{\rightmargin}{#2}%
\setlength{\listparindent}{\parindent}%
\setlength{\itemindent}{\parindent}%
\setlength{\parsep}{\parskip}%
}%
\item[]}{\end{list}}

\begin{document}
\section{foo}
\begin{frame}[t]
Text
\end{frame}

\begin{frame}[plain,t]
\begin{changemargin}{-2cm}{0cm}
Text
\end{changemargin}
\end{frame}
\end{document}

-

The class beamer loads the package geometry by default. The package geometry provides the command \newgeometry which allows to change the page settings inside the document.

Here an example:

\documentclass{beamer}
\usetheme{Berkeley}
\begin{document}
\section{foo}
\begin{frame}[t]

Text
\end{frame}

\newgeometry{margin=1cm}
\begin{frame}[plain,t]

Text
\end{frame}
\restoregeometry
\begin{frame}[plain,t]

Text
\end{frame}

\end{document}


-
Thanks. I double-checked, the theme was Berekeley, and posted a screen into the quietion itself. –  eudoxos Nov 10 '11 at 16:57
Oh crap, the geometry does not get restored properly :-| I put screenshot of the question edit... –  eudoxos Nov 11 '11 at 18:02

Related to this earlier question:

\documentclass{beamer}
\usetheme{default}
\setbeamersize{text margin left=1ex} % Beamer manual, section 8.3
\begin{document}
\begin{frame}[plain,t]
Here's some more content. Here's some more content. Here's some more content.
\end{frame}
\end{document}

-
that solution doesn't work inside \begin{document}. The command uses \geometry. You can use \newgeometry instead. –  Marco Daniel Nov 10 '11 at 17:35
What doesn't work inside \begin{document}? Not following. –  Mike Renfro Nov 11 '11 at 2:23
The command \setbeamersize works only in the preamble. So you can manipulation a single frame with this command. –  Marco Daniel Nov 11 '11 at 8:31
@MarcoDaniel: confirming that { \newgeometry{margin=1cm}\begin{frame}[plain] ... \end{frame} } works. Can you write it as answer so that it is visible and I can accept it? Thanks! –  eudoxos Nov 11 '11 at 8:39
@MarcoDaniel: I did :-) –  eudoxos Nov 11 '11 at 8:58