Actually, BLANK and NULL are not the same.
An easy test is to append a blank record to a cursor with a null enabled field. ISBLANK(name_of_field) return .T.
ISNULL(name_of_field) return .F.
Conversely, if you REPLACE name_of_field with .NULL.
ISNULL() return .T. and ISBLANK() returns .F.
You can also blank fields and records with the BLANK command.

>I believe it is because the value is null not zero. To solve this modify the table to have a default value of zero for that field.
>
>>Why, in VFP 6, in newly added records, do numeric fields appear blank instead of showing zeros? I notice this 1) on a form, where the control sources for the objects are the numeric fields, and 2) when I browse the table.
>>
>>It creates a problem in my form since I've marked the objects SelectOnEntry, but SelectOnEntry doesn't appear to work on the objects where the control source is a numeric field which has yet to have a value entered into it.