I wanted to add that I have a HC-SR04 that doesn't work with NewPing 1.2, 1.3, or the 1.4 pre-release, using either the Simple NewPing Example Sketch or the 15-sensor example, modified for 1 HC-SR04. It works fine with the example code at TrollMaker.com is for sale | HugeDomains though.
How can I help debug the library for the HC-SR04?
EDIT: Forgot to add that I'm using an Arduino Uno r3 with the v1.0 Arduino IDE.
EDIT2: I get 0cm like everyone else with an HC-SR04 reported. I even tried getting the raw timing data instead, in case it was an obscure bug in the distance conversion. Everything I get is 0.
EDIT3: In case it's helpful, I note that I can hear the HC-SR04 sending out its sonar pings when I try NewPing. So I would guess that the bug doesn't involve actually sending out the pings.