Yep, it was exactly as I suspected. Check your PM's, I sent the fix back to you.
The reason this is happening is because your duck animation isn't looped. Once it gets to the end, animations stop. You have to kick them back into gear with "Play animation." And to insure that your animation always starts on the first frame, use "Set animation frame to 1."
And like I said before, the Trigger Once condition will insure that you don't activate the set frame and play animations actions over and over again every cycle.
Nice looking sprite, by the way.