I don't know if this is an issue with React or IE11 but when an the input initially contains an EN-dash (8211) it fires the change event. 
JSFiddle http://jsfiddle.net/uH539/10/

ReactDOM.render(<div style={reset} />, container);
      expect(stubStyle.display).toEqual('');
      expect(stubStyle.left).toEqual('');
      expect(stubStyle.top).toEqual('');
      expect(stubStyle.fontFamily).toEqual('');
    });
    
    it('should update styles when mutating style object', function() {
      
      spyOn(console, 'error');
      var styles = {display: 'none', fontFamily: 'Arial', lineHeight: 1.2};
      var container = document.createElement('div');
      ReactDOM.render(<div style={styles} />, container);
      var stubStyle = container.firstChild.style;
      stubStyle.display = styles.display;
      stubStyle.fontFamily = styles.fontFamily;
      styles.display = 'block';
      ReactDOM.render(<div style={styles} />, container);
      expect(stubStyle.display).toEqual('block');
      expect(stubStyle.fontFamily).toEqual('Arial');
      expect(stubStyle.lineHeight).toEqual('1.2');
      styles.fontFamily = 'Helvetica';
      ReactDOM.render(<div style={styles} />, container);
      expect(stubStyle.display).toEqual('block');
      expect(stubStyle.fontFamily).toEqual('Helvetica');
      expect(stubStyle.lineHeight).toEqual('1.2');
      styles.lineHeight = 0.5;
      ReactDOM.render(<div style={styles} />, container);
      expect(stubStyle.display).toEqual('block');
      expect(stubStyle.fontFamily).toEqual('Helvetica');