David,

I think you might be right about that. What would make the Valid() not fire? I think I will take Erik Moore's suggestion and strip the form of all code except those relevant controls and see if I can eliminate the cause. When I press the Save button to do the TABLEUPDATE those bottom 3 comboboxes act as if I pressed the Cancel button and did a TABLEREVERT.

Here is a sequence of events:
1. Chose values from all 4 comboboxes without problem
2. Pressed Save, but only #1 combobox saves, last 3 comboboxes reset to prior settings
3. Pressed Edit and re-chose values from last 3 comboboxes without problem
4. Pressed Save, but only #2 combobox saves, last 2 comboboxes reset to prior settings
5. Pressed Edit and re-chose values from last 2 comboboxes without problem
6. Pressed Save, but only #3 combobox saves, last comboboxes reset to prior setting
7. Pressed Edit and re-chose value from last combobox without problem
8. Pressed Save and #4 combobox saves