If you put two activator rails side by side (not connected) and put two minecarts over it, the activator rail pushes the minecarts off the rail towards south.

Steps to reproduce:
1- Create a track of 3 rails with an activator rail in the middle.
2-  Create a second track of 3 rails with an activator rail in the middle. (the activator rails must be side by side)
3- Place a minecart over the activator rails (one for each activator rail).

Observed result: 

• The minecarts get pushed toward south direction with no redstone or power rail.

• The same scenario does not reproduce if facing east/west.