I just upgraded my prs-300 to the 10.alpha version, worked fine, thanks for the hard work.
I changed the default book font to Fontin following this guide:
http://translate.google.com.br/trans...n&hl=&ie=UTF-8
To create the font, I used this program:
https://www.mobileread.com/forums/showthread.php?t=71999
If anyone want change the default font and uses the Sony Reader Library program, you'll have to put your modified font on the Sony Reader Library installation folder or it will mess with the pages flow when you copy a book to your reader using it.
I tried this because I don't like the left justification in epubs but the sony default font for lrfs files is a bit ugly.
Sorry my bad english. ^_^