Insert mode - point doesn't move to next line

I'm having an issue with the master branch where the cursor in Insert mode doesn't always move to the next line with Return or Ctrl-J. I can reproduce this in the following way: 1. open a new buffer with `:new` 2. Go into Insert mode with `i`. 3. Type `hello world` 4. Hit Enter, the cursor goes to the beginning of the line just typed and not the next line. This also happens intermittently in eshell where when I enter a command like `ls` the cursor moves to the beginning of this line rather than the prompt that comes up after the output. Thanks ... -deech