Thanks for the link
Tested it and says all is well.
Still need to get to the bottom of the speed reduction problem and why when I am paying for 20m I am only geting 3-4m.
in fact speed check from top of forum rates present speed as
Your connection speed is 3.85Mb, you have indicated that you are meant to get up to 20.00Mb from Virgin Media
off to nag VM again