Severe ghosting on animated objects when camera stops moving in sequences when using path tracer

Pixels seem to stop updating in the path tracer when a camera stops moving in sequence. Old color values from objects that have moved seem to still affect pixels they should not. 

1. Create a new level sequence
2. Add a camera to the sequence and animate it to move for the first half of the sequence, and to be stationary for the rest.
3. Add a sphere to the sequence and animate it for the whole sequence
4. Add an object in the background to contrast the sphere against, keep this stationary
5. Save the sequence and render it with the "Use Path Tracer" setting checked

RESULT

When the camera stops moving there will be severe ghosting of the sphere for the remainder of the shot. ([See attached video|[Link Removed]])

EXPECTED
The object should not leave a ghosting trail, as seen before the camera stops moving.