How long does an ignition coil last on a 2002 Corolla? on 2002 Toyota Corolla

I had an ignition coil changed in 03/08/2011 and today the same mechanic tells me I need an ignition coil. Can this be possible? Its been only 7 months.

Asked by for the 2002 Toyota Corolla
I don't see too many ignition coil problems on Corollas. Was a it a good brand coil or some cheap off brand coil? A bad spark plug could cause premature coil failure but 7 months is very strange. Was the failure P0301, P0302, P0303 or P0304?