engineer fixed my broadband now, QAM164 had changed to QAM256 he said, he's fixed loads of cabinets with this problem. He said its due to the rollout of 100mb.
Getting around the full 20/2mb speed now
Usenet is still capped at 10mb 24/7 though even though this violates virgin's terms of conditions, i should get 20mb until i download too much when it should go to 5mb.