Capture the output, HTTP headers and all, and send it to us to look at. Also if you can provide the exact date and time, that will help us locate your request in the logs.
Ensure you have not hardcoded the IP addresses for
api.supertweet.net or if you do hard-code the IP addresses, make sure they are all still valid and be prepared to check it once in a while and update your code with valid IP addresses from a DNS lookup.