I have had TiVo for just over a year now, and still loving it. Only problem I always have is BBC iPlayer. It ALWAYS buffers. I have no problems with anything else. All other on demand is perfect, even in HD - no buffering or problems. Also YouTube works without stalling in the middle of a video, its just iPlayer.
Also, I have a V HD Box, the catchup iplayer on that works fine, but Im aware this isnt the BBC app thingy that tivo has.
Does anyone know if this is a problem with virgin and the internet connection, the app running on the tivo software or the BBC's servers???
Seems to either be an issue with the data through the VM network or quite possibly (likely) capacity issues at the BBC (or more specifically whatever third party they use to deliver the content).
I believe iPlayer content via V HD is still hosted by VM with the BBC sending them the assets. iPlayer via TiVo I believe is streamed direct from the BBC/third party provider hence perhaps why the former works fine but the latter doesn't.
But do those other apps use Virgin's network to play content from the above CDNs?
Perhaps you're getting a degree of packet loss or latency from those CDNs - both of which can have a dramatic effect on network throughput. For example, a TiVo has a dedicated 10mbit/s line but just 1% packet loss is enough to reduce that to an effective 2.3mbit/s. Take it to 2% packet loss and you're down to 1.7mbit/s and latency can have a similar effect on that throughput value.
Since even SD content requires a consistent throughput of at least 1.5mbit/s, it's easy to see how even a small problem with the network could be causing the problems you're seeing.
I'd ask Virgin to look at your network connection; specifically the ping time and the packet loss between you and the above CDNs, because each of those CDNs have plenty of bandwidth to deliver seamless content to many thousands of clients so the fact that you can't watch a single stream without serious buffering really does suggest a network issue.