ADSLGuide Spped Test Problem

I can hit the full download rate of approx 850 KB/s (8mbps) from a number of websites. However ADSLGuide speed test always reports extremely poor speeds in the 1.1mbps range, as seen here:-

http://www.thinkbroadband.com/speedtest/results/id/117636227139364929225.html

Any idea why this speed test reports such low figures? Could it be that certain paths on the TalkTalk network are slower then others?

Routing is a real possibility as maybe traffic shaping which is why we've added a port 80 option.

Just noticed that - I'll give that a go...