@oddman5,
Without seeing the epub it isn't possible to be certain, but you should look at the css file contained in the epub with a text editor and look for instances of font-family:xyz; or font-family:"xyz";
One or more of them is probably not set to match your userStyle.css.
You can edit the css and replace it in the epub, then try it again on your reader.
If you're using Calibre to manage your books, the Tweak-epub option is your friend.
|