Activator Rail Ejection Inconsistencies.

At some times, activator rails behave "normally" and eject mobs and players to the same block, diagonal to the rail, every time, regardless of if there is a place for the mob/player to land. At other times, ejection is inconsistent. Sometimes the mob/player will be ejected to the diagonal block, while other times it will be placed on the rail. Being placed on a rail can even happen when blocks are above the rail. Also, whether or not a mob/player can be ejected with a block underneath them seems to fluctuate. There are some instances where the mob/player will simply not be ejected. I can not identify exactly what causes these inconsistencies. I originally thought they were location based, but locations which exhibited one behavior, changed behavior later. I also noticed that when mobs/players where ejected regardless of whether there was a block to stand on, those locations seemed to be more consistent. This might have been coincidence, though.