Even nama-aparadha is not ordinary, it is high-class. Nama-aparadha is of so many of kinds and gradations, not only one kind; for example one of the varieties is vaishnava-aparadha. Actually, it is very good that one is chanting nama-aparadha. That will bring one to nama-abhasa, nama-abhasa will bring one to suddha-nama, (pure chanting of the holy name, wherein Krsna is revealed as non-different from His name) and that will bring one to a still better stage, prema-bhakti...