Pocketing operation in prismatic machining

Dear sir:

I meet some problem during programming a pocket operation.

like pic show, i have a simple pocket with 2 islands, which one is with a taper wall and top face equal to the pocket top face, another one is with straight wall and top face is lower than the pocket top face.

  1. the lower top face of the island is not recognized, the area above the island top face is also not machined.
  2. the taper wall of the island is not recognized, it still show a straight path around the taper wall.
  3. if i erase the island features which is auto recognized from the bottom face choose, i cannot select the two islands, it only support one island selected.
  4. and the finishing path only support the whole pocket bottom plan, do not support the top face of the island finishing.

how to deal with these cases.

Thanks in advanced.

Kim