ExtJS 4.x: How to disable “dirty record” red corner in Ext.grid.Panel cells?

Its working again in ExtJS 4.1.1.
Use the markDirty configurationProperty in the gridview.

When you have a GridPanel, use it like this:

viewConfig:{
    markDirty:false
}

http://docs.sencha.com/ext-js/4-1/#!/api/Ext.grid.View-cfg-markDirty