Series 2 channel changing issues

I have TWC cable. They recently updated to digital channels. My Series2 won't change channels with the DTA box and IR cables. I have tried numerous codes and nothing is working. I have tried 3 sets of IR cables, 2 calls to Tivo and 2 techs from TWC have come out in the last 2 weeks. Can someone give me any other ideas? I love my Tivo and have a lifetime on 2 units that I cannot use as they are.

Thanks