Why is this still a problem after 5 years?
Googling reveals this has been an issue since 2009, and apparently with every release of Arduino since! Tracking down and using the custom-built rxtxSerial.dll works fine (old fix - haven't yet tried Frederico's fix yet), but it's very disappointing that this has not been fixed by the powers-that-be years ago. Is this the normal mode of operation with Arduino?
* Replaced RXTX library with JSSC (Alexey Sokolov)http://code.google.com/p/java-simple-serial-connector/