I want to stack Ethernet shield and USB host together with my Arduino MEGA 2560. Each of these shields works fine separately. Is it necessary to contact bootloader pins with each shield and arduino board? I have connected and tried, but the problem exists.

only one shield works fine at once.(always the sheild that directly connect to the Arduino board). How do I resolve this problem ? I want to work all 2 shields at once.

these are the sheilds I have used.

1. [Circuits At Home USB Host Shield v2.0][1]
2. [Ethernet Shield v5.0][2]

Thank you [1]: http://shieldlist.org/circuitsathome/usbhost-v2 [2]: http://shieldlist.org/arduino/ethernet-v5

I want to stack Ethernet shield and USB host together with my Arduino MEGA 2560. Each of these shields works fine separately. Is it necessary to contact bootloader pins with each shield and arduino board? I have connected and tried, but the problem exists.

only one shield works fine at once.(always the sheild that directly connect to the Arduino board). How do I resolve this problem ? I want to work all 2 shields at once.

these are the sheilds I have used.

1. Circuits At Home USB Host Shield v2.0
2. Ethernet Shield v5.0

Thank you