problem with firefly and arduino uno

hi guys

I have a little problem with my fantastic new arduino: after installing all the drivers, firefly and arduino software, the board is connected with the computer, the  COM port show data flow from the sensor and firefly firmata is uploaded to the board, UNO read element in grasshopper doesn't show any data flow. someone has an idea about this problem. I followed all the step of the firefly tutorial and I have tried different usb port and to reboot the system but nothing. the strangething is that the arduino interface when firefly Boolean toogle is open says com port used from other software so is seems to me that is actually reading something.

really appreciate any answer

cheers guys