@dlowan,
Phew.
Been almost impossible to get in for a day or so. No response from A2k support, so I did try ISP. Rude as usual. It's funny what strong cultures businesses have! Norton and HP support are ALWAYS a delight to deal with, even when we are struggling to understand each other. Microsoft is always unreachable.
They're not interested in investigating the problem since it's only gone on for a month and today unplugging the modem and re-plugging it coincided with being able to access A2k again. (As if I hadn't done that before!)
They refuse to believe it's just one site because I haven't "monitored it". When I said I had been monitoring it for over a month and it was always just A2k they said it wasn't important enough yet to be investigated.
BUT...I AM free to look for a better provider!!!
Will likely wait until I get back from overseas though.