I`ve come to a room w/clear green back ground(it want let me pass thru). On the other side is a worker and an alien looking-guy(more like pumkin-head)to the left inside you can see a checkpoint, but the worker also cannot walk thru it(clear background).I use the charm to get the worker to pull a switch and a small platform is revealed at one doorway and the doorway I`m at has a room to enter. Inside the room is small platform above water to walk on. To the left corner is the small platform(the worker opened) I can`t jump to it and it appears to be clear green also. In the cenetr of the room is a big canister that a machine keeps dropping green barrels into, they spin around and fill it and empty into it(I guess this keeps the green background for doorways)I`ve doubled back and checked EVERYTHING????

Never mind......You have to use a regular jump to the platform and then kill the alien dude and make it to the checkpoint.