I have a subform that uses the DLookup function as a Default Value for one of its fields. It does a DLookup on a field in the main form and tries to populate based on the result. For a while it was working without any issues but seems to intermittently break.
What the field will do is generate an accurate default value before the subform has been entered while the user is still completing the main form. Then once the user enters the subform to enter records, the default value will disappear from that field and the field will be null or blank and the user will have to manually enter the value.
I'm not sure what is causing this but there is another default valued field next to the suspect one which does not use DLookup and is simply set to duplicate a field value on the main form. This default value never resets itself and works fine.
Any help will be much appreciated,