Activator rail glitch

I was making an activator rail road and when I got in my minecart to test it out. When I reached the activator rail I suddenly got kicked off the minecart, and it kept doing this to me. I looked at the minecart and it was vibrating on the rail. Really quickly shaking and I kept mining it and trying again. Please help. The seed was -153608108 and I was playing on a flat creative peaceful world.