IO Expansion Shield For Arduino Mega V1.2 and xbee S1 code upload

i have the dfrobot expansion shield V1.2 and a funduino mega 2560 R3 and i also have two series 1 xbees. I programmed both xbees through x-ctu and uploaded the example physicalpixel on my arduino with usb cable and xbee removed from shield. when i put the xbee back in the shield and plug in a 9v external supply and plug in the other xbee through the pc with the xbee explorer when i press H and L the light on arduino light up and turns off so my xbees are comunicating no problem. my issue now is when i go through the arduino ide and select the com port of the xbee and click upload after the code compiles and wants to upload i get
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer?
what am i doing wrong?

this is how i configured my xbees

xbee transmitter (pc)

PanID: 4136
DL: 10
MY: 11
Baudrate: (7) 115200
D3 DIO3 configuration: (3)DI
IC DIO change detect: 8
DD Type identifier:10000

Xbee receiver (arduino)
PanID: 4136
DL: 11
MY: 10
Baudrate: (7) 115200
D3 DIO3 configuration: (5)DO high
IA IO input address: FFFF
IC DIO change detect: 0
DD Type identifier:10000

thanks.