title: Multiple react form inputs disables the onSubmit
body: <p>I have this very simple example that works as expected:
  <a href="https://jsfiddle.net/x1suxu9h/" rel="noreferrer">https://jsfiddle.net/x1suxu9h/</a></p>
  
  <pre><code>var Hello = React.createClass({
    getInitialState: function() {
      return { msg: '' }
    },
    onSubmit: function(e) {
      e.preventDefault();
      this.setState({ msg: 'submitted' })
    },
    render: function() {
      return (
        &lt;form onSubmit={this.onSubmit}&gt;
          &lt;input type="text" /&gt;
          &lt;div&gt;{this.state.msg}&lt;/div&gt;
        &lt;/form&gt;
      )
    }
  });
  </code></pre>
  
  <p><strong>However</strong>, when adding another form field, the onSubmit is not triggered anymore when pressing the enter key: <a href="https://jsfiddle.net/nyvt6506/" rel="noreferrer">https://jsfiddle.net/nyvt6506/</a></p>
  
  <pre><code>var Hello = React.createClass({
    getInitialState: function() {
      return { msg: '' }
    },
    onSubmit: function(e) {
      e.preventDefault();
      this.setState({ msg: 'submitted' })
    },
    render: function() {
      return (
        &lt;form onSubmit={this.onSubmit}&gt;
          &lt;input type="text" /&gt;
          &lt;input type="text" /&gt;
          &lt;div&gt;{this.state.msg}&lt;/div&gt;
        &lt;/form&gt;
      )
    }
  });
  </code></pre>
  
  <p>Am I missing the obvious here?</p>