Qas on another forum did some investigating.
According to him the issue is on BT's link to the 'LINX' secondary public peering network', which happens to be where TBB traffic travels to BT. He hasnt found it on any other routes.
Also it seems right now BT are playing with the routing tbb uses as I am having to browse this forum with one of my proxies currently.
BT Infinity 2 Since Dec 2012 - Estimate 65.9/20 - Attainable peak 110/36 - Current Sync 70/20, Current Attainable 68/23

Edited by Chrysalis (Mon 25-Mar-13 12:39:28)