Thought i'd share this...

My router DownStream Connection Speed was showing about 11054 kbps but the speed test sites eg Namesco BroadbandMax ADSL Broadband Bandwidth speedtest | Test your ADSL Broadband connection speed were showing about 3.5-4Mbps connection.

my network card was set with a receive buffer size of 8Kbps (Control Panel -> Network Connections -> [Your SKY Connection] -> Properties -> Configure -> Advanced)

maybe it was causing false readings or maybe it is actually slowing down data between the router and the computer... but I set mine to 64kbs and my "speed" reported by speedtest sites increased from a 3-4Mbs average to a 9.5Mbs average.

hope this helps someone