We've seen some problems with requests coming in out of order. What makes this problem especially ugly is that we have an implicit save going on. When you change feeds and filters too quickly, or for any number of reasons there's a hiccup somewhere and the requests make it into the back end out of order, the result is that you may overwrite your newest changes.
To fix this, I'm storing a revision key/value in the mixing spec. I'm also making save explicit (that is, explicit in the code, not in the user experience currently). Save will happen in a separate ajax request. The response to this request will either be a 200 (OK), 400 (Bad request, i.e. missing revision number) or 409 (Conflict). In either of the error cases the front end will be receive a response with the current server-side revision number. I solicit your feedback. Greatly appreciate. -R
