I remember the "Next Page Preview" function from when I initially started using Little Reader and have been trying to turn it back on today without any luck. Then I read this handy tip and noted that the next page preview only works for "Word only (Flash)" and "Picture only (Flash)".
I love using "Word, Media" with my 11 month old son, probably because I have had great success with YBCR and my daughter and I am most familiar with this style.
Is it possible for you to add the "Next Page Preview" to the other playback modes?
Of course you might need to change the name from "Next Page Preview" to "Next Word Preview".