I'm trying to use the Serial library to send and respond to Arduino. But when running the Simple Write example in Processing, there is a consistent 7sec delay between my mouse event and the LED turning on the Arduino. I've tried a number of solutions and wonder if any experts here can help me out.

My failed solutions:

- Fixed the rxtx version mismatch according to this post

- Got same delay on Processing 1.5.1 and Processing 2.0a6 on Windows 7 (with RXTX fix; Arduino is only COM port listed)

- Got same delay on Processing 1.5.1 on Mac 10.5 (with RXTX fix)

- Reinstalled Processing 1.5.1 on Windows 7 and included the Arduino-Processing library. The sketch runs despite the version mismatch but experiences the same delay.

Is there any other way I can get 2-way communication between Arduino and Processing over USB? Any suggestions will be greatly appreciated!