Artathart, I had just the opposite experience with my Accubrite! Instead of making me feel better it's made me worry more. When I set up the incubator it read 99.8 steadily for hours, placed on the wire in the center of the 'bator. The glass thermometer that came with the 'bator said 100.2 or so. Well, I added the water and the eggs and turner, and now the Accubrite has been holding steady at 98.2-98.4 ever since. I had to move it to the side of the 'bator to be out of the way of the turner, so I'm hoping that's why. The glass thermometer taped to the inside lid still reads 100.2. I figure if I average the two readings then the temp's probably about right. I'm not sure what I'd do about it anyway.
I've been looking at YouTube videos of candling, and now I definitely want to give it a shot at Day 7!