When a pop-up menu or drop down control is set to display data from a field and the value in the field is NOT a member of the selected value list the two controls in question show the actual value in the field. This gives a confusing presentation to the user especially where the value list is attached to a numeric foreign key field and the list is defined as having a table source with the pk and text values, show only second field.
Consider list source table:
and primary table:
Presentation is solid and user only ever sees the "value" column from the list source table until the list source table changes (through deletion or deactivation)...
List source table:
|Header 1||Header 2|
After this change to the list source table the Primary table record number 2 will show "214" in the drop down or pop up menu control. This is behavior is not easily explained to the novice user, could be an impediment to adoption, and is normally overcome by building kludgy functionality (layered controls and the hide object when flag for example) to control the user experience.
This behavior of these two controls under this condition should be controlled from the inspector in the control style section so a developer can set/define the behavior without workarounds.
Possible solutions would be to add a choice control to the inspector Control Style section for the two controls in question that asks the user to make a choice what value they want to show in the control if the actual field value is not a member of the list.
Choices could be show nothing/empty/blank, show calculated value, or show actual value.