Hi, I've done this and it still doesn't work. I've got a super hub 2 in modem mode connected to an Apple Airport Extreme. I've added the DNS addresses and reset the router and tivo v6 box and it still doesn't work.
I have the exact same set up as you (Apple Time Capsule connected Virgin SH2 in modem mode) and I followed your instructions and put in the DNS servers and then rebooted the V6 but I'm still getting the errors (V312 when accessing the Netflix app and A01 Leapfrog-Netflix when trying through channel 204). I got the V6 a week ago and have not managed to get Netflix working through the V6 even once. Very annoying! I am loathed to phone up customer services as I know that I'll be passed from pillar to post and they probably won't solve the issue.
I can also access Netflix on my Apple TV box and PS3 but it's an annoyance to have to switch over to those devices when the V6 *should* support Netflix!