Dunlop Sportmaxx's perchance? These are particualry prone to wearing badly on the inside edge. But the way the geometry is set up is harsher on the inside edge than you might expect. Its a trade off to better handling.
I had exactly the same issue (with Dunlop Sportmaxx's), the centre tread had plenty of life but the inside edge was fubard. I had the alignment checked and it was found to be spot on. For what it costs its worth getting checked for peace of mind though...