Yesterday I had my carpets cleaned. I unplugged and removed my desktop tower from under the desk and decided not to put it back the same day, as the carpet was still damp. Instead I fired up my laptop to read the mail.
I don't have pop3 email set up on that machine, so I went into gmail with firefox. I haven't done that for a long time. And I got completely stuck. I really thought that lever thing under the trackpad that you use for clicking (what's it called by the way?) had given up the ghost. In the end I shut the browser window, then started again. And this time I got a prompt asking me if I wanted to use the default interface or the "traditional html" one. I opted for traditional and suddenly everything worked normally.
What has Google gone and done to its interfaces?
PS: I've found a partial answer
here.. It seems I'm not the only one who's been having problems.