At any stage, have you tried reseating the TurboNet card? I had a similar problem (see http://forums.oztivo.net/showthread.php?t=1887) which was resolved when I swapped TurboNet cards (luckily I have 2 TiVos). Both TiVos have been working flawlessly ever since, which implies that somehow the TurboNet wasn't sitting quite right.