[Ripplinger]

Make sure the caps are also exactly the same. A font file named Font-Regular.otf will not work if the path name is FONT-REGULAR.OTF.

Are you switching books to force the font to load? Opening the same book with a changed css file won't show any change.

How are you changing the fonts, through PRS+ Settings, under Book Viewer Settings and then User EPUB Style (CSS File)? Or trying to change an individual epub by converting with custom css info?

For PRS+ custom files, my path for the css files is \database\system\PRSPlus\epub. The path for the font files is \fonts. A typical css file is below that changes the font only, no special spacing or anything else.

Can you upload the 2 fonts somewhere that don't seem to work and one of us can try to see if they work for them to help pinpoint the issue?

@font-face {
font-family: "LexiaDaMa";
font-weight: normal;
font-style: normal;
src: url(res:///Data/fonts/LexiaDaMa.otf);
}

@font-face {
font-family: "LexiaDaMa";
font-weight: bold;
font-style: normal;
src: url(res:///Data/fonts/LexiaDaMa-Bold.otf);
}

@font-face {
font-family: "LexiaDaMa";
font-weight: normal;
font-style: italic;
src: url(res:///Data/fonts/LexiaDaMa-Italic.otf);
}

@font-face {
font-family: "LexiaDaMa";
font-weight: bold;
font-style: italic;
src: url(res:///Data/fonts/LexiaDaMa-BoldItalic.otf);
}

body {
font-family: "LexiaDaMa"; 
}

Edit: I installed the Palatino fonts from this site and they do work on my reader. It is quite similar to the default, but you can easily see the difference if you take a screenshot of the same page in the default font, or whatever other font you were using, and then Palatino.