i only experience this problem when I'm editing using visual editor with text inside an html table.
If I hit a shift+return or hard return it initially adds a line break or paragraph return. I can save my change just fine.
If I go back and save again, or do something else and hit update, it strips my line breaks or paragraph returns completely and jumps it all together. It almost seems like there's a stripslash going on in my content.
This happens inside html tables. Is there a function that could prevent this or block this from happening?