It seems that some images in my media librarybgot lost when I migrated this site from Wordpress.com. In some of my early posts, I also linked to images on an old website which no longer exists.
If you come across a post with missing or broken images, please let me know by posting a comment, and I'll get them fixed. I have all the images, I just need to upload them and tag them to the article. Simple but tedious work, which is why I haven't got round to it yet!