minecart keeps stopping and kicking me out,

Put the summary of the bug you're having here
when i'm in a minecart, and run across a acceleration track it kicks me out.
What I expected to happen was...:
Describe what you thought should happen here
I thought that when you hit one of these track you were supposed to keep going not stop
*What actually happened was...:*the minecart stops and puts me out
Describe what happened here

Steps to Reproduce:
1. get in mine cart and start moving on track. when you get to the red track keep going, not stop
2. ...
3. ...