... and try the same thing at the Netduino. Disconnect the RS232 break out board, and then connect D0 to D1.
That will allow you to verify the Netduino's serial code.
Sorry for the late reply on this.
I swapped over the PINS and it seems the netduino isnt receiving any data, although the TX light flashes on the serial shield to indicate activity. Could this be something to do with my Netduino?