My blue tongue wont eat

Question
I have had a captive bred blue tongued skink since April of 2011.  He/she was born per the breeder in August of 2010.  My blue tongue seems to be growing quite rapidly so a month ago we got him a 40 gallon tank with new lighting.  Recently his eating habits have been off.  He will only eat about once or twice a week and for the past week he hasn't eaten at all.  I've tried different varieties of food.
Help!

Answer
I need more information before I can hazard a guess.  
Reptile go off feed for a variety of different reasons (but there is always a reason).

Health problems
Environmental problems
Stress
Hormones

So, before I can take a stab at helping you figure out the issue, I need more information:

A full description of the equipment you are using (light, heat, etc), exact temperatures, humidity, etc.

A full description of the diet you have been feeding him.

His current weight.

Any other changes in behavior.