>>All strange things used to happen in Friday. This is one of them. Imagine that you open list portion of combobox, browse by mouse over there and leave the area without selection (e.g. just click on some other control). It's not very nice (but understandable) to find out that Combo.Value is not corresponded to RowSource.Field anymore, but the worst case is that Listitemid or Listindex properties go nowhere after this action.
>>Can it kill some App logics? I just tested this for 3.0b.
>>Any comments?
>
>What about resetting the properties in Combo.LostFocus() ?

Yes, following Combo.Lostfocus construction will help
cValue=this.value
this.value=""
this.value=cValue
But it's unbearable to code it for any combobox.
Nick, can you make me a favor and make quick test in 5.0a and post the results here.