This one has been a problem for us on several occasions. For example, right now we are getting the usual, uninformative:
"message": "The provider did not accept the message: unknown response received"
This being due to the DDOS attack on DynDNS this morning (as best as I can tell).
Yesterday Twitter suspended our app (briefly) because it needed to go through a review. The same error as above was returned by the oneAll API.
Having more detail about the provider response inside the OneAll API response will make troubleshooting and error handling much easier.