Add or replace with this in extra java opts. Seems there was a bug fix and this worked, just not sure when. Its worth a try
-Dgnu.io.rxtx.NoVersionOutput=true
I also noticed this on the link you provided…Unless you have any specific reasons, this is the recommended download. If you need to be compatible with javax.comm.* then download RXTX 2.0. Not sure what javax.comm is, maybe it means generic?