Originally Posted by ischeriad
MacEachaidh, this sounds like you are experiencing dithering on text? I had the impression dithering only concerns images/pictures. Dithering seems best for photos while diagrams look better without most of the time. In some books, I toggle a lot.
You're correct, in the sense that the term "dithering" is usually only used in relation to bit-mapped graphics -- though technically it also applies to generated and recorded sound as well. The term usually applied to text is "anti-aliasing", which is basically the same idea, but applied to the edges of curves and lines rather than areas of shade or colour. iRiver confirmed that the term "Dithering" on the options menu referred to text display; since text on an e-Ink display is bitmapped rather than anti-aliased vector graphics, it's probably the right terminology for them to use.
I understand what you say about diagrams: curves and diagonals, in particular, don't fare very well when bitmapped. In application, I guess it's a matter of personal taste; since I use my Story almost exclusively for text-only documents, I prefer the dithering switched on.