JIT release transfers zero qty

When we change the delivery date or quantity of the existing schedule line and we trigger a new JIT release, it transfers the old schedule line with the old delivery date but with zero qty.This also happens when we delete an existing schedule line, it also transfers zero qty.

Sample:

1st Release

Line 1: 3/10/2015, 10

2nd Release

Line 1: 3/9/2015, 5 (changed)

Line 2: 3/12/2015, 15 (new)

Is this the standard behavior when we change/delete an existing schedule line of the SA in ECC?

Thanks.