Error : invalid deductee serial no. in form 26q

Hi all,

While filing the TDS Return for this Quarter (i.e., Q1 2013-14), Annexure to form 26Q displays the following error :

"Invalid deductee serial no. for added records. Deductee serial no. for added records should continue from the last deductee serial of corresponding challan."

While earlier, this column was optional, from this FY it has been made compulsory. Can anyone advise as to how this column has to be filled?