Maybe it has something to do with the joystick/button adding 5% (and rounding), then the playmaker proxy doing a 'on value changed'. maybe the proxy sees a change and thus changed the float value.
If true, is there a way around this?
UPDATE: When it messes up (mouse click on slider then use keyboard/joystick) and does it wrong at 15% increments (add or subtract),
then I click on another window like the scene and
then click back on the game window, it fixes it.
It will now go up or down at 5% increments (not 15%) Weird.