Part. Velocity causing AB particles to rotate

[aldred2]

The problem is with the attached file. If you look, you can see the AB particles turning 180 degrees after birth. The regular Pflow particles don't rotate. This happens when I switch on Part. Velocity in Alignment. Switching to None fixes it, but I need the velocity for stretching.

Is there anything I can do to fix this in AB, or am I going to have to look for a different solution?
Thanks
Mark