Within Mike Taylor’s demo for Introducing the HTML5 History API, you’ll find this note:

window.addEventListener('popstate', function(e){
 // be nice to Chrome, the spec changed
 // and they haven't caught up yet
 // http://code.google.com/p/chromium/issues/detail?id=63040
 if (history.state){
   self.loadImage(e.state.path, e.state.note);
 }
}, false);

Per Chromium issue 63040, Chrome dispatches a popState event on initial page load. This was okay when HTML5 history was first introduced, but then the spec changed. It’s been over a year, and the bug still persists.

The easiest hack/solution, as proposed in comment 11, is to add the popstate listener right after the initial page load, in a setTimeout.

setTimeout( function() {
  window.addEventListener( 'popstate', myPopStateHandler, false );
}, 10 );

I’m weary of throwing a setTimeout in for a resolution, always seems like a kludge. But for now, hey it works.