I'm seeing every few calls to the Directions API result in a 403 error with the "not a valid key" message below. Identical back-to-back calls will succeed and then fail. I tested this key and our app 100s of times about a week ago and never saw this error, but now it is regularly failing. Please help.
"This is not a valid key. Please check that you have entered this correctly. If you do not have a key, you can obtain a free key by registering at http://developer.mapquest.com."
P.S. I submitted a help request with the "Contact Us" link so if someone is already looking into this thank you and please ignore this new request. I didn't receive any reply so wasn't sure if that one went through.