Ball won't fall and speed up/down platforms.

Hi there,

I am really new to Unity and for Uni have been asked to design a simple game. I have gone for a sort of golf platformer where you control the ball using W,A,S,D and have to take it towards a target after getting over some obstacles that are in the way. Really simple stuff but I have run into a couple of problems, the first you can see at the screenshot below:

http://cl.ly/0C3d08393Y0R2W1c0k09

I have applied a rigidbody to the ball and it runs smoothly down the platform until it gets to the last 'target point' where it decides not to drop and will just float above it. Any ideas?

Secondly if you look at the screenshot below again:

http://cl.ly/0h2s3P0E3K3P233I2P1U

I have two platforms and I would like one half to be speed up, the other to be slow down. I think I would have to use OnTrigger to accomplish this but not entirely sure, can anyone help here? If possible I would also like as it passes over the speed up that some particles are emitted and a basic sound.

Any help would be great!

Thanks