Deployment of Calc on Ubuntu Server

Dear all, after successful installation of Collect on our Ubuntu Server we are now struggling with Calc. We setup the tomcat server and installed all relevant R packages (incl. rJava). When we access the page our.server:8080/calc we can see the page but it freezes immediately. However it is not starting. The log files catalina.out show a problem with the JRI path: "Cannot find JRI native library!". The JRI library is installed under /usr/local/lib/R/site-library/rJava/jri. However, I am not sure where to set this environmental variabl as there are so many different files in ../tomcat7/bin. Should we specify the path in setenv.sh?? or later in catalina.sh ...? Any suggestions welcome. Greetings Paul