title: R cannot find package
body: <p>On REHL5.7, after I used <code>install.packages("randomForest")</code> in R command lines, I get:</p>
  
  <pre><code>installing to randomForest/libs
  ** R
  ** data
  ** inst
  ** preparing package for lazy loading
  ** help
  *** installing help indices
    converting help for package 'randomForest'
      finding HTML links ... done
      MDSplot                                 html
      classCenter                             html
      combine                                 html
      getTree                                 html
      grow                                    html
      importance                              html
      imports85                               html
      margin                                  html
      na.roughfix                             html
      outlier                                 html
      partialPlot                             html
      plot.randomForest                       html
      predict.randomForest                    html
      randomForest                            html
      rfImpute                                html
      rfNews                                  html
      rfcv                                    html
      treesize                                html
      tuneRF                                  html
      varImpPlot                              html
      varUsed                                 html
  ** building package indices
  ** testing if installed package can be loaded
  * DONE (randomForest)
  Error in library(randomForest) :
    there is no package called 'randomForest'
  </code></pre>
  
  <p>No error is prompted. Does anyone know how to fix or debug this problem?</p>