Next triggers for a change in any header field value.  (Any field prefixed with an "H." in the field listing).  Make sure none of the header field values are changing in your source data and it should work.

Only fields prefixed with "H." using the "Replace" operation will trigger the Next number so if you use Calculated and reference the source column using IMP$[x] where x is the column number, it will not trigger the Next number if it varies from one record to the next.  It sounds like you are referencing the dollar amount in a header (table or temp) field with the Replace operation.  If you are trying to calculate a running total for the header, try instead using either a temp field or the table field with the Calculated operation and add it to the value being read, you could use something like the following if the header or temp field is numeric.

Temp001=Temp001+NUM(IMP$[x])

Only fields prefixed with "H." using the "Replace" operation will trigger the Next number so if you use Calculated and reference the source column using IMP$[x] where x is the column number, it will not trigger the Next number if it varies from one record to the next.  It sounds like you are referencing the dollar amount in a header (table or temp) field with the Replace operation.  If you are trying to calculate a running total for the header, try instead using either a temp field or the table field with the Calculated operation and add it to the value being read, you could use something like the following if the header or temp field is numeric.

Temp001=Temp001+NUM(IMP$[x])