Where the Secretary of State has adjusted the amount payable under a maintenance calculation under the provisions of regulation 10(1) and (3A) of the Arrears, Interest and Adjustment of Maintenance Assessments Regulations and that maintenance calculation is subsequently replaced by a fresh maintenance calculation made by virtue of a revision under section 16 of the Child Support Act or of a decision under section 17 of that Act superseding an earlier decision, that adjustment shall, subject to paragraph (2), continue to apply to the amount payable under that fresh maintenance calculation unless the Secretary of State is satisfied that such adjustment would not be appropriate in all the circumstances of the case.