Particle Designer 1.3.6 was released today. This is a very small update that moves the Randomize button in the GUI away from the play/pause button.
This was not our best design moment and could catch people out. The GUI is being thrown away for PD 2.0 and we will put design decisions like that behind us :) but hope this small change will stop the swearing that can occur when hitting the button by mistake.
Mike