What that means is that the film tried to rewind but could not. When It happens to me, I change batteries, turn it on and depress the rewind button. Film rewinds and it's good to go again.

I usually get 3 to 4 rolls of film before the batteries get run down enough to not rewind. Or about 4 to 6 weeks if it doesn't take a lot of pictures.

My low battery lite is not on. the batteries can have enough juice to run the camera but don't have enough to rewind the film after awhile.

Hope this makes since to you, it's crystal clear to me..