ping))) to flash issues.

I've created a simple circuit of a ping)) connected to the arduino and used serproxy to send this data to flash. This works fine - usually.

Right now for example it has stopped working and I have no ida why, on the ping))) there is a flashing LED to indicate it is working, When I open arduino and use the serial monitor this is working fine. However with serproxy running as soon as the flash movie runs and it tries to connect to the socket the light stops blinking on the ping))) and teh value are either passed through as 0 or null.

I'm pretty stumped as to why this works sometimes, but sometimes not, any ideas??