Hi, There seems to be a problem using the mega stem shield with the new Due. The com locks up and you are unable to load programs with it attached. After uploading, the shield can be attached and things seem OK … till you want to do any program changes that is. The stem shield was not designed for the Due but perhaps a revision would make it compatible. It seems that the simple reset circuit on the stem shield may be the problem. Just thought people would like to know.
A quick fix to the problem is to simply remove the RST LED from the board. 
It’s not hard to do 
. I used a small set of pliers and just twisted it off. Its important to be sure there is a clean break between the LED solder pads when your done. On my version there’s a silkscreen triangle ( indicating the eradicated LED’s polarity not doubt ) that you can see to be certain that all is clear 
.
The RST button on the stem shield appears to still work after this 
. The RST on the Due is accessible with the shied on anyway if your fingers are not too fat. Needless to say there won’t be a red flash from the shield anymore after this and perhaps the warranty is voided as well. Gotta love a good quick Hack fix though.
BTW The same fix works with the Stem Basic Shield 1.2 as well.
It would have been a major drag if we couldn’t use all the cool Grove stuff with the Due.
I hope that Seeedstudio make a revision to the existing shield or makes a Due model. In the meantime I hope the Hack helps 