"R extension on RapidAnalytics (Linux)"

Unknown

I'm having trouble detecting a problem with R on RapidAnalytics.

I've got the following installed on an x64 Debian:
RapidAnalytics CE 1.3.013
R Extension 5.3.000
R version 2.15.1
RJava 0.9-3

If I run processes without R nodes, it's fine, but whenever I try to use an R operator it makes the entire RapidAnalytics service to crash.
With status logging turned on, that was the output:

2013-10-03 16:09:05,260 INFO  [org.apache.cxf.transport.servlet.AbstractCXFServlet] (http-8080-1) Servlet transport factory already registered 
2013-10-03 16:09:06,064 INFO  [de.rapidanalytics.ejb.RepositoryEJBImpl] (http-8080-1) gaspar submitted process to /home/gaspar/Try1/ts_proba (1264 characters)
2013-10-03 16:09:06,515 INFO  [org.apache.cxf.transport.servlet.AbstractCXFServlet] (http-8080-1) Servlet transport factory already registered 
2013-10-03 16:09:06,624 INFO  [de.rapidanalytics.web.tools.ProcessServiceDelegate] (http-8080-1) Scheduled process execution /home/gaspar/Try1/ts_proba with parameter ID 163. Will fire first at Thu Oct 03 16:09:06 CEST 2013.
2013-10-03 16:09:06,670 INFO  [de.rapidanalytics.ejb.ProcessJobEJBImpl] (QuartzScheduler_Worker-9) Starting process /home/gaspar/Try1/ts_proba with thread priority 5.
2013-10-03 16:09:06,723 INFO  [de.rapidanalytics.ejb.ProcessJobEJBImpl] (QuartzScheduler_Worker-9) Job /home/gaspar/Try1/ts_proba was assigned id 163
2013-10-03 16:09:06,728 INFO  [de.rapidanalytics.execution.ProcessExecutionDispatcher] (QuartzScheduler_Worker-9) Registering process execution queue DEFAULT (SimpleProcessExecutor).
2013-10-03 16:09:06,728 INFO  [de.rapidanalytics.execution.ProcessExecutionDispatcher] (QuartzScheduler_Worker-9) Dispatching job 163 to queue DEFAULT. (SimpleProcessExecutor)
2013-10-03 16:09:06,753 INFO  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Process context is: Macros: [_ra_user : gaspar, _ra_jobID : 163]; Input: []; Output: []
2013-10-03 16:09:06,755 CONFIG [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Logging process to file statuslog
2013-10-03 16:09:06,755 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Initialising process setup.
2013-10-03 16:09:06,759 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Process initialised.
2013-10-03 16:09:06,759 INFO  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Process //_LOCAL/home/gaspar/Try1/ts_proba starts
2013-10-03 16:09:06,760 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Process:
   Process[0] (Process)
    subprocess 'Main Process'
      +- Generate Vector[0] (Generate Vector)
2013-10-03 16:09:06,761 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Defining context macro: _ra_user = gaspar.
2013-10-03 16:09:06,761 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Defining context macro: _ra_jobID = 163.
2013-10-03 16:09:06,765 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Starting application 1 of operator Process
2013-10-03 16:09:06,767 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Executing subprocess Process.Main Process. Execution order is: [Generate Vector (Generate Vector)]
2013-10-03 16:09:06,768 FINE  [com.rapidminer.Process.1] (QuartzScheduler_Worker-9) Starting application 1 of operator Generate Vector

And nothing after that.
What can I do to find out what caused the crash? Is there a way to log the execution process of the R extension?

Some additional info:
- R extension and its operators are displayed on the web interface (so it can be loaded)
- If I unset the R_HOME environment variable: it doesn't crash but complains that the R extension could not be loaded.

Thank you for your responses in advance.