A user recently changed his Mac machine and has a 2007 model of a MacPro with an Intel inside.
At the time of writing, he is not able to connect to his logger yet.
Hence, I did a check on how RXTX is advancing.
Here is a small recap:
RXTX is distributed at http://rxtx.qbang.org/wiki/index.php/Download) .
Looking for some more info there, brought me to http://rxtx.qbang.org/wiki/index.php/Installation_on_MacOS_X . A valuable update was done in february 2009. I do not know if that is integrated in the distribution at the download link.
So that 'update' points to http://iharder.sourceforge.net/current/java/ where one can download librxtxSerial.jnilib . I do not know what that is worth, but it can be tested using the zip distribution, putting the file in place of the location where it is originally sought.
If you test this jnilib and it works for you, let it know here. I might build yet another webstart version, but I do not want to mutliply versions of that.