>In SQL server let's say you actually see in the field. In Access the only way to tell is to run a query with a criteria of Is Null or = "". I did verify that your fields are "". A work around would be to use CStr([FieldName] & "") in your query to convert the NULLs to zero-length strings. These you can compare on.
In my quick test this suggestion did the trick:
SELECT Table1.f1, Table1.f2, Table1.f3
FROM Table1 INNER JOIN temp ON (Table1.f1 = temp.f1) AND (temp.MaxOff2 =cStr(Table1.f2 & "") );
