After restoring a new larger hard drive to each of my two TiVos I found that the TiVo software was indicating the unit was detecting a hardware error and that I should do a reset to clear the problem. The message also indicated that if the reset did not clear up the problem I should call TiVo and report error #51. Doing a search on this forum was no help with this error number (that I could find anyway). On my Humax the error message said to call Humax and report error #51. My first conclusion was that Time Warner did something to cause the problems, but before blaming them I decided to call TiVo as directed. I called and reported error #51 which the tech never heard of. After going though a number of hoops with him, we determined that the TiVo would not record in any mode. Since the hard drives were just installed I had not yet gotten that far in getting the units ready for normal use. After jumping through some more hoops he said the software was corrupted and I needed to do a clear and delete everything to return the unit to factory specs. I have just completed doing this on the Humax and the error message is gone. The unit seems to record normally in manual mode which it would not do before, so the "clear and delete" seems to be the magic fix for this particular error message. I will initiate the process on my series3 tonight before going to bed so it will be ready for the new guided setup in the morning. I am hoping this process will not screw up my cable cards which I just got working again after a power outage and several Time Warner visits.