title: Unexpected behavior of R after install on another EC2 instance
body: <p>I'm fighting this problem second day straight with a completely sleepless night and I'm really starting to lose my patience and strength. It all started after I decided to provision another (paid) AWS EC2 instance in order to test my R code for dissertation data analysis. Previously I was using a single free tier <code>t1.micro</code> instance, which is painfully slow, especially when testing/running particular code. Time is much more valuable than reasonable number of cents per hour that Amazon is charging.</p>
  
  <p>Therefore, I provisioned a <code>m3.large</code> instance, which I hope should have enough power to crunch my data comfortably fast. After EC2-specific setup, which included selecting Ubuntu 14.04 LTS as an operating system and some security setup, I installed R and RStudio Server per instructions via <code>sudo apt-get install r-base r-base-dev</code> as <code>ubuntu</code> user. I also created <code>ruser</code> as a special user for running R sessions. Basically, the same procedure as on the smaller instance.</p>
  
  <p>Current situation is that any command that I issuing in R session command line result in messages like this: <code>Error: could not find function "sessionInfo"</code>. The only function that works is <code>q()</code>. I suspect here a permissions problem, however, I'm not sure how to approach investigating permission-related problems in R environment. I'm also curious what could be the reasons for such situation, considering that I was following recommendations from R Project and RStudio sources.</p>