Bukkit

• Updated to 1.6.4 (DEV Build) (Fixes http://dev.bukkit.org/bukkit-plugins/bookshelf/tickets/68-noclass-def-found-error-class-not-found-exception-on/)
• Fixed multiple "Empty Result Set" errors (Fixes http://dev.bukkit.org/bukkit-plugins/bookshelf/tickets/66-unexpected-crash/)
• Fixed using apostrophes in shelf titles (Fixes http://dev.bukkit.org/bukkit-plugins/bookshelf/tickets/67-sqlexception/)
• Set Block Break priority to "MONITOR" (Should prevent books from dropping even when the shelf shouldn't break)

I hope this fixes some of the bugs you guys are having. I have been busy with school, so sorry about the slow and small update. Enjoy!