ComboBox selected value not set when changing field focus

[spotk]

Hello list,
I'm facing a little problem with combobox.

I've a form with multiple fields , i've a combo defined as :

{
			xtype: 'combo',
			id: 'cartes_cb',
			fieldLabel: 'carte',
			hiddenName: 'numero_carte',
			selectOnFocus:true,
			displayField: 'numero',
			valueField: 'numero',
			iconClsField: 'id_membre',
			store: this.cartestore,
			anyMatch: true,
			anchor:'100%',
			typeAhead: true,
	        triggerAction: 'all',
			allowBlank: false
		}

When the user enter a text to filter the combo store, and one value is returned , the combo field is populated, but if the user use tab key to pass to the next field without explicitly clicking in the combo field , the value is not defined correctly.

Is this a known problem?

Maybe someone knows a trick for this?

Thanks in advance

Spotk

[Condor]

Some notes:

{
  xtype: 'combo',
  id: 'cartes_cb',
  fieldLabel: 'carte',
  //hiddenName: 'numero_carte', -> valueField == displayField, so use name instead
  name: 'numero_carte',
  selectOnFocus:true,
  displayField: 'numero',
  //valueField: 'numero', don't specify if valueField == displayField
  iconClsField: 'id_membre', // <- this is not a standard config option
  store: this.cartestore,
  anyMatch: true, // <- this is not a standard config option
  anchor:'100%',
  typeAhead: true,
  triggerAction: 'all',
  allowBlank: false
}