I have a facility that serves as a wool farm.  In this farm a minecart loops through a enclosed herd of sheep then up over a viaduct.  At the top of this activator rails eject the sheep to water channels to the left and right where they are carried to a dispenser that shears them before returning them to the herd.  In past versions the ejection was left and right.  Now the sheep are being ejected in line with the rail stranding them on the viaduct and breaking the facility.

Note:  It has been some time (months) since I operated this facility so I cannot say exactly when this changed.

How to duplicate: 

1. Lay a section of powered minecart track with a powered activator rail on a raised section.  

2. Put a sheep (or other mob) in the cart

3. Launch the cart and note the location of the sheep (mob) after ejection