Originally Posted by speedy2
As long as it is an M Card you should be fine and since you used it in a 4 tuner TiVo with success your good to go.
That is not necessarily true. There are some m-cards with older firmware that only support 4 tuners. See this thread
Edit: Since the OP is a Time-Warner customer and therefore presumably has a TA for SDV support , there is also a potential problem there.