I too recently have noticed several lost notes. I am not sure how they disappeared. I work on a Mac Mini, a Mac Book Pro, and iPad and an iPhone. I entered some of the missing notes on my Mini, which is never turned off. Some were entered on my Mac Book Pro. I have had several meetings lately, and went looking for a note I specifically know I entered and it has vanished. I am searching by 2 peoples names I know are in the note. All of my systems are set to sync every 15 minutes......should I shut down the auto-sync? This is very concerning to me, as Evernote is mission critical to my work. I am very interested to see if we can come to any resolution about this.