Do you mean TCD648250 or TCD658000?
Unitron -- Thanks for the interest, I am the lucky owner of a TCD648250B with 2 month old 500gb internal drive.
After some troubleshooting, I discovered my (tivo usb wifi) internet connection was fine with 85% signal & after reboots, I could connect/update Tivo services quickly with no issues.
All network diagnostics ran fine.
I resolved this issue by deactivating my netflix account on the tivo, then re-activating. In my case, the key was to access the Video on Demand Netflix setup immediately after reboot & tivo service update, otherwise the Video on Demand menu would generate an error & NetFlix would not be selectable.
After reboots, sometimes my video on demand would not load & sometimes it would appear briefly, but disappear after I tried to connect to netflix.
Whenever I actually tried to play netflix, it would not load & ultimately disappear from my now playing list. hmmm
This is how I resolved:
*I unplugged wifi usb & rebooted system.
*Plugged in wifi & verified network settings & password, connected & updated Tivo Service.
*I immediately went to Video On Demand & selected Netflix > Netflix Account Information > deactivate device.
*I then went to netflix.com & added my tivo as a new device > Entered activation code on Tivo & now all is running fast & flawless for last 2days.
Anyways, hope this helps someone else.
I find NetGear routers do not play nice with a lot of devices.
Perhaps there is a security setting blocking the tivo. If you haven't already, might be worth assigning a static IP to the tivo & enabling port forwarding in your router settings for the IP address you created for your Tivo.
I have discovered a lot of info by visiting the amazon.com item page & searching reviews for the issue, other people likely have same issues