I have a new series 2 40hr tivo and I would like to upgrade it with a 160gb WD HDD. I have upgraded several in the past but all of a sudden I am having trouble with this one. In th past I would just run "BlessTiVo /dev/hdx" and that was it. But now when I do that(and I have tried with 2 diffrent HDD's) with this Tivo it will boot to the power screen, then almost there, then go black and reboots itself. My question is what am I doing wrong? Is it because it is a Western Digital? What is the diffrence between BlessTiVo and MFStools?