I've noticed that when I was editing the application and left the window open for a long period of time (maybe 30 minutes - 2 hours) I would find that clicking 'Update' would return an error. I'm not sure if Refreshing my page helped, but when I clicked the back button my application would be saved. I only remember it from the trauma of the prospect of losing my data. I thought it was a time-out issue.

This happened to me a while ago, I would say late August, early September.