Fibre broadband download slower than upload

[#1]

Checked the speed today and found download of around 4Mb/s instead of my usual in excess of 16 Mb/s while the upload speed was 5Mb/s, the same as when last speed checked in October 2013.
Any suggestions please?.

[#2]

Are these Speed Test results from http://speedtest.btwholesale.com?
If they are, would you be able to try connecting directly to the modem and testing again please?
Help on this can be found here: http://community.plus.net/library/broadband/fibre-help-how-to-set-up-a-pppoe-dialler-in-vistawindows...