Would you be able to try the new bootloader mentioned here: http://arduino.cc/forum/index.php/topic,64105.0.html on one of the problem boards? (I don't have any theory as to why this would result in a change, but it would be worth a try...)
Would you be able to try the new bootloader mentioned here: http://arduino.cc/forum/index.php/topic,64105.0.html on one of the problem boards? (I don't have any theory as to why this would result in a change, but it would be worth a try...)