I was having a problem with slow program downloads from the TiVo to my PC. It would take right around 60 hours to download a 1.1Gb file.
Turns out that it was the NIC in my PC that was causing the problem. There is a feature in many NICs that offload some housekeeping chores from the PC onto the NIC. It turns out there are some compatibility issues due to lack of standards for this feature.
Anyway turning off the 'checksum offload' and possibly the 'packet offload' for my NIC fixed my slow downloads.
Just thought I would share this since I never did see any mention of this in the forums.