Originally Posted by elemenoP
And also: what does this dialog box mean: "affects only books opened afterwards!" The book I'm currently reading isn't affected? How about if I open another book and then open the book I was reading again? Is it affected then? Or does the setting only affect books I've never opened (those with the "New" icon)?
You are definitely not using the latest PRS+ which would be PRSP_650_2.1.02alpha.
You are, most certenly, using 2.0.18 which only applies custom CSS once, when a/the file is opened - not necessary a untouched new one, but it has to be opened from the file-system again.
So with 2.0.18 it is/was necessary to open another book, and change then back to the original one to see the CSS applied.
With 2.1.01a and 2.1.02a the epub-file will be reloaded by code. The CSS changes are applied immideately.
The extra-options - jackie mentioned - are included in the font-size-dialog, you get when you push the SIZE (Magnifier) Button.
For more info please see the WIKI
on the project page. (Scroll down to Extended SizeOverlay for x50)
[EDIT] Just reread your post, and you mention there you installed the latest none alpha/beta code, which IS 2.0.18.
But IMHO it is well worth to try almost a full year of code-development which you find in 2.1.02a - even while alpha-state it is, most of the time, stable and safe to use