Well, one thing you definately don't want to do is wire things up wrong and fry something in your house. First off, are you sure the 100A panel is wired correctly? How long is the run to the new box, what type/size cable is used and how many wires are there in that run? Is it an attached or detached garage? What size/type breaker is in the main panel?
Are you sure you are hooked up correctly from the 100A panel to the compressor. Should be two hots and a ground. How long is the run to the compressor? What size wire from 100A to compressor? Make sure the right connections are made in the compressor box. On mine, there are two poles to the pump/motor and two from the breaker, then the ground. Make sure these are according to the manual.