Thanks so very much ladies. I had completely forgotten about the feet and the importance of keeping them clean. Of course, after being reminded by you all, I gently turned the TM on it's side and, lo and behold, it's feet were grubby, to say the least (what an admission to have to make). Anyway, I cleaned them and, you're right, the scales are fine again. Thanks again so much.
I still cannot believe how much I love my TM - just made Tenina's citrus curd, and it's fabulous. So much so that I am going to make loads and put it in pretty little jars, and give them to my foodie friends for Christmas!