Because I do not have root privileges on some of the machines I use, I build part of my software from source and install it into my own homedirectory. Doing that requires one to download R from CRAN, e.g. R 2.14.1. Compiling R now is a matter of running:
tar -xzvf R-2.14.1.tar.gz ./configure --prefix=/home/usrname/local_software make; make install
I recently had to upgrade R, thus forcing me to repeat this process. I had been using RStudio already for a while, therefore I was very surprised to see that it failed to start. RStudio could not find R, and thus failed to start. Before re-compiling R all was fine. It turned out that the problem was related to the shared library of R. By default, the R shared library is not built. RStudio needs it, and thus my RStudio was crashing. To solve this, you need to adapt building R a little bit:
tar -xzvf R-2.14.1.tar.gz ./configure --prefix=/home/usrname/local_software --enable-R-shlib make; make install
Adding the extra configuration flag causes the R shared library to be built, fixing the problem with RStudio.