The default for those pins should be INPUT unless something changed them. Can you show me where that is happening?If in fact those pins were both set to OUTPUT, then the Due is as half-baked as the wifi shield. edit: I believe you now. I checked the schematic, and it appears there are two SAM pins connected to each of D4 and D10. I gotta wonder what designer/programmer would do something like that? Good thing I am not the boss there. Those guys would be looking for a new job tomorrow.
// remove this one pinMode line. Leave the digitalWrite pinMode(10,OUTPUT); digitalWrite(10,HIGH);