Thanks Luke. I'll just let everyone else know what I told you by PM. The strangest thing seems to have happened. I logged in with my Wife's account on my Mac, and there isn't a problem on hers. I've logged back in on my account, and have been on here for about 15 minutes now, without any popups. It seems to be OK now. Fingers crossed.
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You meet the nicest people on a Honda.
I went back on my Wife's account for half an hour, without ant problems. I've totally reset Safari in my account, and will see if that cures the problem.
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You meet the nicest people on a Honda.