Shannon wrote:
I was having this problem too just then, and then realised that you have to put the number up to around 1000 to register any actual rewinding - it's in milliseconds!
I finally figured it out yesterday. I found out the ideal place to set it at is 400. It's set at just enough words, around 1-1/2, before the new words are heard. As far as being impressed with the player, it works for me most of the time. The only thing that could be better is that sometimes it makes the doctors sound kind of "tinny-sounding."
Thanks, Melody and Shannon, for offering your help. 
Teri