A couple strings changed to undefined after editing. I don't know if that might be because I had been logged out perhaps. I know I had to re-login shortly thereafter. Could that be what happened? Otherwise what would "undefined" mean in this situation?
Yes, being logged off would definitely be the reason. If you are logged off (for example, you leave the AMOS Translator page opened for a while without touching anything), strings can not be staged via AJAX call.