title: Can't use either View() or edit() functions, getting "Error in .External2(C_dataviewer, x, title) : invalid device" error message
body: <p>I'm running R through the Terminal in a Mac OSX Snow Leopard system. </p>
  
  <p>I get this error message when trying to use <code>View(</code>):</p>
  
  <blockquote>
    <p>Error in .External2(C_dataviewer, x, title) : invalid device In
    addition: Warning messages: 1: In View(a) :   locale not supported by
    Xlib: some X ops will operate in C locale 2: In View(a) : X cannot set
    locale modifiers 3: In View(a) :   unable to create fontset
    -<em>-fixed-medium-r-</em>-<em>-</em>-120-<em>-</em>-<em>-</em>-<em>-</em></p>
  </blockquote>
  
  <p>And this error message when trying to use <code>edit()</code>:</p>
  
  <blockquote>
    <p>Error in .External2(C_dataentry, datalist, modes) : invalid device In
    addition: Warning messages: 1: In edit.data.frame(a) :   locale not
    supported by Xlib: some X ops will operate in C locale 2: In
    edit.data.frame(a) : X cannot set locale modifiers 3: In
    edit.data.frame(a) :   unable to create fontset
    -<em>-fixed-medium-r-</em>-<em>-</em>-120-<em>-</em>-<em>-</em>-<em>-</em></p>
  </blockquote>
  
  <p>I can't find information about this particular problem. What can I do to fix this?</p>
  
  <p><code>sessionInfo()</code> returns:</p>
  
  <pre><code>R version 3.0.1 (2013-05-16)
  Platform: x86_64-apple-darwin10.8.0 (64-bit)
  
  locale:
  [1] C/UTF-8/C/C/C/C
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base     
  </code></pre>