Beamer notes "show notes on second screen" option does not work

I want to use the “show notes on second screen” option for beamer. Here’s my code (MWE):

documentclass{beamer}
usepackage{pdfpages}

setbeameroption{show notes on second screen}

title{TEXPLORE}
author{Todd Hester}
institute{University of Texas at Austin}
date{December 3, 2012}

begin{document}

begin{frame}
titlepage
end{frame}

begin{frame}
frametitle{Robot Learning}
begin{itemize}
item Robots have the potential to solve many problems
item Moving from controlled to natural environments is difficult
item We need methods for them to learn and adapt to new situations
end{itemize}
note{Robots have the potential to be very useful in society, by doing tasks that no one wants or is able to do. However, they are currently limited by the need to hand-code them for most tasks. Therefore, we need methods for them to learn from experience in the world.}
end{frame}

end{document}

When I try to compile, I get:

! Undefined control sequence.
KV@beamer@option@show notes on second screen ... 
                                              {two screens with optional...
l.5 setbeameroption{show notes on second screen}

Here are the versions from the top of the compile output:

This is pdfTeX, Version 3.1415926-2.4-1.40.13 (TeX Live 2012/Debian)
restricted write18 enabled.
entering extended mode
(./slides-test.tex
LaTeX2e <2011/06/27>
Babel <v3.8m> and hyphenation patterns for english, dumylang, nohyphenation, uk
english, loaded.
(/usr/share/texmf/tex/latex/beamer/base/beamer.cls
(/usr/share/texmf/tex/latex/beamer/base/beamerbasercs.sty)
Document Class: beamer 2010/06/21 development version 3.10 A class for typesetting presentations (rcs-revision a6b1a8434d30)