I was getting annoyed with the slow and jerky behaviour of the blog when scrolling down or when pressing "page down". I guessed that it might be the re-painting of the screen with the background picture. Having turned off that setting, it now scrolls properly.
The other day I also changed the post colours to pure white on pure black rather than light grey on dark grey. I hope that improves things a bit for those who don't like white on black. I'm inclined to keep that for the posts because it does provide a much better setting for photographs.
Some time soon, I will adjust the picture to show more of the Tiber - at the request of Sir Dan of the Nesbitry.