Are any other brands of expanders compatible with the Tivo pvr besides Tivo's own expander(the one by Western Digital). The Good Guys have said an ordinary Western Digital one will work with my Tivo. Joyce Mayne have said no,only the Tivo branded one that is made by Western Digital will work with Tivo. The thing that is the worry for me is that the Western Digital is about $100(but it might not work when I get it home) and the Western Digital/Tivo expander is between $230 and $299. I have been offered othe brands of expanders by other retailers for between $90 to $100 but I am confused as to wether they will work.