Date fields cannot be empty & don't have a value

I have a recurring problem with edittexts. It does not always happen, but sometimes.

When databinding an edittext to a db table and a date field to give it a datepicker, sometimes it's not possible toempty the field after a value has been entered.

For example the user enters '31.12.2012' into the field (by typing or using the datepicker) and then tries to remove the date with the delete or backspace key.

The moment the form focus is set on a different item, SBO automatically re-enters the previous value into the edittext.

Even setting the edittext variables Value and String properties to an empty string or to null does not remove the value in the form.

However, the value is an empty string in code.

Likewise, if the user removes the value and then leaves this form item, SBO re-enters the value in the form, but in code the value is empty.

I need to check if the user has entered a date or not, but this way a date is displayed for the user, but in code it does not exist.

Is this a bug in SBO?

Is there a way workaround that allows me to

A) allow the user to empty edittexts with datepickers

B) get the true value of what really is displayed on the form in my code?

PS: it seems to happen randomly and even copying an edittext (in Screenpainter) from another form in where this problem does not happen, only adjusting unique id and position, does not help.