I have a dual drive v2.5.5 UK (Thompson) Tivo. There appears to be no way to upgrade this as some of the system MFS files are stored on the second drive... You can restore to a single drive but using TivoMAD then deletes the partitions from the other drive and screws up the system.

From what I read I need to start from a real single-drive image otherwise it won't work. I have this 120gig drive looking rather useless at the moment...

Can anyone point me at somewhere to download a suitable image?