Thanks for the replies chaps. Not sure why, but the solution seems to have been to point at the EU server (As suggested by Sir Alan)....see below: -

http://www.hpmuirt.com/images/temp/BTC%20Guild%2072%20hours-2.JPG

As you can see, as soon as I switched to that server, my reported speed and thus rewards came back up to normal and have remained there.

Cheers n beers

HPmuirt