I'm working on a ATMega168 version of Ardupilot. I have added the airspeed sensor shield. As far as I can tell (from the leds and voltmeter readings) I have put it together properly. Today I downloaded Ardupilot software version 2.1.2. I did modify the constant definition "SHIELD_ENABLE to 1. Then I uploaded the code using Arduino-15. Because I have the shield I did not disconnect my EM406 GPS.The upload was unsuccessful and the Arduino IDE stopped responding. I tried again while observing the 3.3V and blue GPS leds on the shield. When the upload started, the leds went off as they should. However they almost immediately came on again, indicating that the GPS was powered up-not good during uploading.So then I disconnected the GPS and uploaded again. This time the 3.3V led went off and stayed off while the upload was in progress, as it should. The upload was successful.Then I tried the Arduino-16 IDE with similar results. The only difference was that the Arduino-16 response was a lot of red error messages when I tried uploading with the GPS connected. With the GPS disconnected, the upload was successful.Anyone else having a similar problem?