Not a big deal, but I thought I should mention this, in case it happens to somebody else:
If you have your MES facing South in the Winter, Spring, or Fall, and you have a window in the door, you could get a false temperature reading at lower temps.
I noticed it when I had the heat set at 110˚, and my MES 40 element shut off while the actual heat in the smoker was about 88˚. I looked around wondering what the heck caused that. It turns out that because the sun is much lower in the sky during the Winter, the sun shines through the glass door, and warms the heat sensor on the lower right side of the back wall of the smoker. Then that tells the smoker it's hotter than it really is.
#1 Turn your smoker to face away from the sun.
#2 Put a curtain on your smoker window, or just lean a piece of plywood against it to block the sun (see below).