The date field is just a text field with a data type of ULCDateDataType in a particular date format. If you input an invalid date format or any non-sensical value - like "48fk49tk", for example, when you tab out of the field the value goes blank. This is the same behaviour as the previous version of ULC. However, when you click back into the field to enter a new value, the old non-sensical value comes back. As far as I can tell, this is new behaviour for ULC 6.1.
I know it does not solve your problem but this behavior has already been the case for ULC 6.0.x.
Etienne
