title: gvim(linux) with r-plugin not recognizing .R files with comments
body: <p>Note: rewrote the original question to reflect the proper solution given.</p>
  
  <p>vim (ubuntu 12.04 w/ r-plugin) doesn't recognize .R or .r files as R files with the r-plugin installed with a comment in the file as shown below.</p>
  
  <pre><code># comment
  x &lt;- 2
  x
  </code></pre>
  
  <p>Without the comment, everything works fine.
  my ~/.vim/filetype.vim reads:</p>
  
  <pre><code>augroup filetypedetect
    au! BufRead,BufNewFile *.r         setfiletype r
    au! BufRead,BufNewFile *.R         setfiletype r
    au! BufRead,BufNewFile *.Rnw       setf noweb
  augroup END
  </code></pre>