RST_TOBJ_TO_DERIVED_TOBJ giving incorrect period

Hello,

In one of my transformation 0DATE is mapped to 0FISCPER till 6th period I got the correct period but from 7th its showing 001.2013.

I came Tto know  this is because of this function module  RST_TOBJ_TO_DERIVED_TOBJ.For Z1 variant its working and C1 its not working and also I found C1 and Z1 variant entries are same in T009B table.Please advice.