I had the same problem tonight. I was using Evernote for lecture notes in my evening class, but when I opened it later to review my notes nothing was there, as if I hadn't made any notes today. I've never had this happen to me. Evernote usually auto saves, but I know I pressed "Done" before I shut my laptop down. If this is a problem with the beta, then I can't accept the risk of losing 2.5 hours of notes.