>> Does changing to another port make any difference?
No, Unfortunately as I have been doing that all week and it will not make any difference.
Again one of the annoyances was that I only started to really notice all this happening was after re-organising my router IP numbers and port forwarding settings on the different computers.
Which obviously I then thought it was my fault and had messed up the system, but then after putting all the settings back to what they were and still not having much luck made me really start to look elsewhere, such as, was it the new laptop I brought at Christmas, the router or switcher I installed a couple of months ago or was it the LAN cable down to the living room, again only recently installed.
Maybe I should try sending Virgin Media a bill for all my time diagnosing the problem which turns out to be their fault, their fault for not keeping their customers up-to-date with what they are doing.
One snippet I also came across said something on the lines of it was mentioned on their site, ha ha, have you ever been able to find anything on their site when you want it?
Edit:
Not that it helps me but might help someone, and that is if using a wireless connection is to try changing the channel number to maybe 3 instead of the popular number 6.