You are not being throttled; you are getting full 8 Meg Sync on your IPStream connection.
You queried speed test results. So where are they?
When you do a TBB speadtest there is a line below "thinkbroadband forum code" within [...]. Put that in your post incl. the .
The BT speedtest you just posted looks not bad; perhaps just a bit low, would expect about 6.6 Meg..
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC