I've got a non-payer of 6 days, I will be put in a DNP at 1.40 pm today, even though he has a 100% positive feedback of 670 with no false positives & nearly all say 'fast payment'.  The last feedback he gave was for 10 sellers on Aug 14 (he seems to give his feedback once a month).

By what U sell, I doubt whether your non-payer started with ua.