Neal, you not alone on this mate, its happened to a few of us, if you look for the thread from lawnmower man, tom has done some ferreting and it seems to be a problem at the server end.
me i know nothing when it comes to computers. as long as the string is tight and wet is as far as my understanding goes.
I've had situations where my PC has been denied access but my notebook through the same system has been okay!!!
it will come back, the longest out I've had was two weeks.