If the heli is dropping at a 45 degree angle, from 100ft, you should not be experiencing the "settling with power" phenomenon. At that angle on descent you should be "seeing" clean air, at least on the forward portion of the disk.

Are you sure you have enough headspeed?

Backing off the collective and applying more forward cyclic should get you going, if in fact you are experiencing the "settling with power" phenomenom.

Rafael