Notwithstanding any other provision of law, except as provided in subdivision (b) of Section 2611, in determining the benefit rights of any person who cannot establish a valid claim pursuant to Section 2652 because he or she is unemployed during the normal disability base period established pursuant to Section 2610, there shall be excluded from the disability base period those quarters during which the person performed no services in employment for 60 days or more and was actively seeking work. For all quarters so excluded, there shall be substituted an equal number of quarters immediately preceding the commencement of the normal disability base period. Benefit rights under this section shall terminate for any disability benefit period that begins when the substitution quarters no longer contain sufficient wages to establish a valid claim under Section 2652.