how big is the shoe box?
what kind of light fixture, reflection and soil are you using?
do you have any air circulation going on?
the effects going on in your plant could be from heat stress. what's the temperature? to lower the heat all you really need is a fan. if you don"t have enough room for a fan i suggest you to get 2 fast speed computer fans. 1 as the intake and the other as outtake, also go to the hardware store and pick up at least 2 or 3 daylight cfl lights with 1750 lumens. this should be way better for your plant.