TiVo has been very stable for 2 years but recently had problems with the TiVo restarting. So decided to start again with the NZ image. Now I get "your recorder is starting up screen" followed by "Maintainace Mode" then the dreaded green "a severe error has occured" going around in loops. Have reimaged this with the same result. Could this be a failed hard drive? Whats the best next step from here? Any advice greatfully received.