chewy,
You can set the default value = (-1, Yes, True) or
(0, No, False).
It would seem, especially if the checkbox is unbound, that
it is not getting initialized.
You could use the AfterUpdate on your combo and if they
have selected the appropriate entry, then:
me.checkbox.visible = True
me.checkbox.enabled = True
me.checkbox.locked = False
and optionally
me.checkbox.value = -1
hth,
Wayne