Scrollbars in Ext 4.1.x and Mc OS X...

...and scrollbars on "Always" in the system settings. This invariably leads to double scrollbars - see attached images.

The window is a border layout (2 thirds, one third split) with a data view and a grid in the center region and a form and toolbar in the east.

The main core of the window code is as follows:

Code:

...
        onRender: function(){
                var me = this;


                me.callParent( arguments );


                me.width = Ext.Element.getViewportWidth();
                me.height = Ext.Element.getViewportHeight();
        },


        afterFirstLayout: function(){
                var me = this;


                me.callParent( arguments );
                setTimeout( function(){
                        Ext.EventManager.onWindowResize( me.fireResize, me );
                }, 1 );
        },


        fireResize: function( width, height ){
                if (width != this.width || height != this.height){
                        this.setSize( width, height );
                }
        },


        setAlignment: function(){
                var xy = this.el.getAlignToXY( this.container, 'c-c' ),
                        thisXPos = xy[0];


                this.setPosition( thisXPos, Math.max( 0, window.pageYOffset ) );


        },


        afterShow     : function(){
                this.setAlignment();
                this.addOverflow();
                this.callParent();
        },


        removeOverflow: function(){
                // only remove the overflow is this is the last remaining *visible* full screen window (you could have one open on top of the other)
                if (Ext.ComponentQuery.query( 'mywin[hidden=false]' ).length <= 1){
                        Ext.getBody().removeCls( this.overflowCls )
                }
        },
        addOverflow   : function(){
                Ext.getBody().addCls( this.overflowCls )
        }
...

Anyone have any experience with Mac OS X scrollbars and has worked out a way to ensure you don't get double ups?