I purchased the SerialIO SerialPort Java package and it worked right out of the 'box'.

I found the SerialIO.com site via the Apple Developer Connection.  I knew it had to be a good outfit if Apple was willing to suggest them as a source.   I purchased the SerialIO SerialPort Java package and it worked right out of the 'box'.  Then, a month later, I ran into a problem which coincided with my purchase/use of a MacPro after my G5 konked out.  Sadly, things did not work on this Intel-based machine.  I was concerned about OS/Java hassles - and wrote to SerialIO support.   Shortly thereafter I got eMail support which helped me isolate the problem and determined I was trying to work with a file that had become corrupted. Thanks to the rapid response from SerialIO support I was able to get back to doing useful work - despite the self-inflicted gunshot wound to my foot.  Here's a collective word out of "You deh Mann!" to SerialIO Support.  

Lance Drake Contract Mac Developer - Santa Fe, NM