I have a editorGridPanel with a combobox on a colomn. everything works but only after a other cell is clicked. is there a way to force the cell to process the data.

this is the code for the combo box
Code:
var successCombo = new Ext.form.ComboBox({    xtype: 'combo',
    triggerAction: 'all',
    store: comboSuccessDS,
    iconCls: 'no-icon',
    valueField: 'perc',
    displayField: 'success_factor',
    tpl:'<tpl for="."><div ext:qtip="{perc} %. {subject}"; class="x-combo-list-item">{success_factor}</div></tpl>',
    allowblank: false,
    resizable: true,
        editable: false,
    grow: true,
    listeners: {
        expand : function(box){
            box.setWidth(200);
        }, 
        collapse : function(box){
            //here i want to force the cell to process the new value
        }
    }
});