I've uninstalled and reinstalled
uninstalled and deleted every file/folder that has tivo in the name
uninstalled and deleted every file/folder, AND every ref to tivo in the registry
Firewall is not activated, no virus software installed. Linksys router with DD-WRT firmware, but should not block anything internal. Tivo is communicating across wireless network without any issues.
Two calls to support haven't revealed anything useful. Their final solution. I had to open a specified list of ports. Did that too, although it was a useless exercise, considering the firewall is turned off on this computer.