Minecart dismounts player when going through activator rail

I have built a small rail system going about 100-200 blocks from a station to a mineshaft location. I typically use 2 activator rails per 16 rails. I hop on the minecart, push it towards the first of these rails, and when i get there I seem to have dismounted me from the minecart with the minecart tipping when going through the activator rails. This is not typical behavior for versions 1.7 and 1.8. In those versions the minecart actually speeds up when passing through the activator rails, but does not tip nor dismounts the player.