I don't use your application (yet), but I do use BasKet, notecase and maemopad.

From a saving perspective, I think you either need to have autosave + a save button (the button for piece of mind), or remove the concept of saving all together, and have a proper "save as you type" type storing that you get with BasKet and OneNote.

One thing that bugs me about notecase is that it does autosave, but to an autosave file rather than the notes file you are editing. So that if you crash out for any reason, you have to recover the autosave and save it over the your real notes file.

I would prefer if it auto-saved in place, and just had some versioning to cater for the situation where you deleted or edited something by mistake.