We make use of a java application that manages a pinpad via the serial port. This works perfectly on windows with the Sun Comm.jar, the supplied dll and the properties file.
We did not change much, nothing in the libraries used. but removing the use of an EventListener on the serial port object fixed the problem.
This actually allowed for our code to work on linux (jre1.4.2, slackware and Suns Comm3 drivers) where this was not a problem on windows - strange.
Phill