title: Error while trying to install R packages
body: <p>I tried to install a package in R by typing:</p>
  
  <pre><code>install.packages("prob")
  </code></pre>
  
  <p>But got error:</p>
  
  <pre><code>trying URL 'http://cran.rstudio.com/bin/windows/contrib/3.1/prob_0.9-5.zip'
  Content type 'application/zip' length 707050 bytes (690 Kb)
  opened URL
  downloaded 690 Kb
  
  Warning in install.packages :
    write error in extracting from zip file
  Warning in install.packages :
    cannot open compressed file 'gss/DESCRIPTION', probable reason 'No such file or directory'
  Error in install.packages : cannot open the connection
  </code></pre>
  
  <p>How can I resolve it? It only happens with some packages, not all.</p>