Yes, I certainly had my share of issues with the one and only RealTrax I.T.A.D. that I owned. It seemed to be incredibly sensitive to room lighting conditions. For example, I would adjust it to work perfectly with the room lights on, but then as soon as I would turn the room lights off to enjoy the layout lights, it would act completely differently.
So then I would tweak it to work properly with the room lights out, but it would act crazy as soon as I turned the room lights back on. It drove me to the point that I finally removed it from my layout and replaced it with a MTH ScaleTrax I.T.A.D (#45-1028). I now use two of these on my layout and have no issues!