I just purchased a 300GB Maxtor DiamondMax Ultra ATA/133 harddrive with a 16MB buffer, the price was too low for me to pass it up. I purchased it at CompUSA with the intention putting it in my PC and pulling .tivo files to in with Tivo-to-go. I then realized that I may just want to upgrade one of my Series 2 Tivos with this drive. Does anyone know if this drive is compatible? I have an 80 hr (black case) and a newer 40 hr (silver case). I am torn as to upgrade the 40 hr since it has the smaller capacity OR I could upgrade the 80 hr because it is older. Any opinions?