I recently opened a notebook of mine and discovered all the various cells (input output, headings, graphics etc) had been converted into one big input cell, complete with date, time etc for each line. I show one line here:
12/17/15 16:58:02 In:= ImageChannels[%]
After laboriously recreating the notebook by cutting, pasting, styling, and after working with it successfully for a while, I saved it and quit mathematica. When I reopened it, the same problem had returned! Why did this happen and how can it be avoided?