AVG TBBx1 DOWNLOAD 0.51mbps
BURST TBBx1 DOWNLOAD 1.02mbps
AVG HTTPx6 DOWN 3.88mbps
BURST HTTPx6 DOWN 6.71mbps
WARNING: Your HTTPx6 speed is vastly different to the tbbx1 result
This suggests an RWIN, congestion or other problem
The speed test looks at various parameters, and in this case there was a large difference between the two download tests. A common cause for this on older computers (e.g. Win XP) is that the RWIN value is too small, connection tweaking software can improve this. Another reason can be congestion, either with the broadband provider or others in the home using the connection.
Hmm none of the above are true, currently using Win 7, no other devices sharing the connection, speed is the same any time of the day or night.
If I had to use the connection myself on a regular basis Plusnet is exactly what I'd be looking to get, fibre I think.