ST 2.1.0 gpl:

I'm running into a problem where at a certain browser window size, the chart goes kind of nutty and messes with the other widgets on the screen. I've managed to isolate it into this test case:
Code:
Ext.application({
    launch:function () {
        this.viewport =
            Ext.create('Ext.Panel', {
                fullscreen:true,
                layout:'fit',
                items:[
                    {
                        xtype:'chart',
                        store:Ext.create('Ext.data.Store', {
                            fields:[
                                { name:'x', type:'float' },
                                { name:'y', type:'float' }
                            ],
                            data:[
                            ]
                        }),
                        series:[
                            {type:'line', xField:'x', yField:'y'},
                            {type:'line', xField:'x', yField:'y'},
                            {type:'line', xField:'x', yField:'y'},
                            {type:'line', xField:'x', yField:'y'},
                            {type:'line', xField:'x', yField:'y'},
                            {type:'line', xField:'x', yField:'y'}
                        ],
                        axes:[
                            {
                                type:'numeric',
                                position:'left',
                                fields:['y']
                            },
                            {
                                type:'numeric',
                                position:'bottom',
                                fields:['x']
                            }
                        ]
                    },
                    {
                        xtype:'toolbar',
                        docked:'top',
                        title:'top'
                    },
                    {
                        xtype:'toolbar',
                        docked:'bottom',
                        title:'bottom'
                    }
                ]
            });
    }
});
What happens is that I see the screen first paint with the top and bottom toolbars showing. Then it repaints and the toolbars are gone and the chart is taking up the entire screen.

I run this in a maximized Chrome window (no dev tools showing) that winds up having document.body.clientWidth/Height = 1920/957. If I make it much smaller than that in either direction, the problem goes away. I also get this on multiple machines. I haven't tested it on a tablet because I don't have any that are nearly that high res.