I am on the 150mb package since it started and have never had any problems. Its now been around 6 months since any speed test has achieved the full speed i pay for. I have been averaging around 50 mb the twice i phoned vm they said there was some work going on in my area (walsall) and could not confirm when it would be complete.the first time they gave me £3 lol and the second time they gave me £4 and a superhub 3 after i asked. My free speed upgrade has been "on the way" forever. However cutting the long story short after seeing your post i tested my speed and low and behold 158.18mbps.
So now if your thinking what im thinking did your tweaking actually work or is virgin media just teasing us as usual?