I purchased the reflexV3 and installed it in a non-FMS plane. Everything works find except when have it in Stabilized mode and increase the throttle the elevator goes down instead of up. Also, in Gyro off and Optimized mode the elevator goes down also. Its on in the correct position when I put it in Stabilized mode. Any suggestions about what could be the problem?

Think about what you are saying. When you add power the nose rises the reflex is sensing this and adjusting with down elevator to keep the plane level. You can test this on the ground (without power)by quickly raise the nose and watch the elevator it should go down.