Just updated to 4.5B46 on my iPhone 5 - I am now unable to create a new secure note. When I try to add a new note I can type in the note, as soon as a I save it, everything entered is gone and a new empty secure note is created.
Nice catch, thanks @rosenkrieger ! I'll be sure to open an issue for this on in our internal bug tracker.
I have the same problem in 4.5B47. Similar result when attempting to edit an existing Secure Note - changes are not saved.
Thanks, this is a known issue, and we'll get this fixed as soon as possible.