Please ignore the earlier message. I didn't realise that if I uninstalled Firefox, then re-installed, it still had all the extensions in it. I thought that I was working with a fresh version of Firefox, and was still having the same problem.
I have uninstalled them all, and the problem has disappeared. Now to add the ones that I need... I love Firefox (normally!) -- Pete Clark Sunny Andalucia http://www.hotcosta.com/comm_1.htm
