Firstly I'd like to welcome you to the forums and say that I'm sorry to hear that you've been experiencing issues with both iPlayer and Netflix through your TiVo box. I'd also like to apologise for the delay in getting to your post.
I can totally understand your frustration on this matter, and would like to help you out. I've run some testing and can see some issues that may cause this fault, so would like to look towards booking a technician to call out for you.
I'll send you a private message in order to get the ball rolling. Please look to the top right of this page where you'll see a purple envelope icon, click on this and you'll see my message.