Famo.us - StateModifiers disappearing?

Question

Wondering if someone might help with another pair of eyes - as I am trying to work out why some of my Famo.us 'Views' are being displayed despite having an opacity StateModifier set to '0'.

Here is my code - My apologies for it not being standard - I have "Panels" instead of "Views" and a few other things..but happy to expand on the code if needed.

function _buildSidePanel() {
    this._sidePanel = _createPanel.call(this);
    this._sidePanel.setOptions(this.constructor.DEFAULT_OPTIONS.sideMenu);
    this._sidePanel.position = this.cm(this.constructor.DEFAULT_OPTIONS.sideMenu.position);
    this._container.add(this._sidePanel.position).add(this._sidePanel);

    this._menuHolder = _createPanel.call(this);  //My version of a View
    this._menuHolder.setOptions(this.constructor.DEFAULT_OPTIONS.sideMenu.menuHolder);

    // Create StateModifiers
    this._menuHolder.position = this.cm({ align: [.5,.6], origin: [.5,.6], proportions: [.9,.8] });
    this._menuHolder.fadeState = this.cm({ opacity: 0 });
    this._menuHolder.sizeState = this.cm();

    this._menuHolder.mC = new ModifierChain();
    this._menuHolder.mC.addModifier(this._menuHolder.fadeState);
    this._menuHolder.mC.addModifier(this._menuHolder.sizeState);
    this._menuHolder.mC.addModifier(this._menuHolder.position);

/*  Tried splitting it to just modifiers but getting the same thing
    this._sidePanel._container.add(this._menuHolder.fadeState)
                              .add(this._menuHolder.sizeState)
                              .add(this._menuHolder.position)
                              .add(this._menuHolder);
*/

    this._sidePanel._container.add(this._menuHolder.mC).add(this._menuHolder);


//    this._menuHolder.fadeState.setOpacity(1,this.constructor.DEFAULT_OPTIONS.sideMenu.menuHolder.transition.in);
  }

I have created a ModifierChain and added among other things an Opacity State of 0. When I add this and then add the modifier and 'View' to the container it displays the View even though the View has a StateModifier of '0' so should not be displayed.

The 'fadeState.setOpacity' command is meant to transition the fadeState to display the View but it is commented out, so the View should not be displayed.

I have this working in other areas so know the approach works. I am also (hopefully) not using the same variable names, so not using a StateModifier more than once. But still stuck as to why this is being displayed.

Any help or thoughts would be gratefully appreciated.

Thanks.