reading an iBook when phone is locked.

Hi all,

A while ago I read about an audio demo relating to being able to have the speak screen feature enabled so that one can have an iBook read while the iPhone is locked. Unfortunately, by the time I got around to listening to the said demo, it was no longer available.
Does anyone know how this works? I turned this feature on but nothing happened when I locked the screen in my book and swiped down using three fingers to read the screen. Though I realized that I forgot to turn VO off; Perhaps that would work but if not, ideas would be appreciated.
Just about every time I'm trying to read an iBook, at a point, VO will stop reading and announce "library". It gets quite annoying especially as it seems the phone hasn't been bumped at the time.
Thanks all. :)