Unless you live in my Cox market. Somehow, they've made it where only the last drive paired works. I've tried drive after drive, in multiple TiVos, reproducing the result. Every time I pair, and all works, I cloned the drive to an identical drive, then installed, to find pairing had to be repeated. I get jumped every time I state this... But, it seems the cablecard knows the drive S/N has changed, and nulls out the pairing. I don't know exactly HOW it can know, I after 20+ attempts, I feel the results show it is the case. I didn't have this problem until the second-to-last time the cards received updated firmware.