Yes, exactly the same but I started again with a new list in case there was a bug in the original list but added identical columns to the original.
Apart from the 2 check boxes almost all are single line text boxes, there is also a choice field and a text box. Nothing fancy going on. I also removed the 'required' option for any fields that had them but it made no difference.
Screenshot of SP list attached.
So it seems like check boxes work in a very simple form but not when more fields are added? Can you replicate this?