I have an application (the only one registered to my account) that makes two requests to the REST API v1.1 every two minutes, both to the /lists/statuses endpoint, and stores the results in a database. The rate of queries does not vary and so should always stay within the rate limit. This has worked successfully for the past six weeks. However, twice in the last week I have suddenly lost access to the API, with any request simply timing out. I have checked my logs and I was not getting any error messages before losing access - the calls were working one minute and then stopped working the next.
I use a shared host so they checked the connection and agreed that the packets were being sent but there was no response. They moved me to a different server, on the basis that my application should not have caused the problem and it may have been another user hosted on the same server. This fixed the problem but today I have started getting no response from the API when I try to access it from the new server. This suggests that my application is the problem, but I have not exceeded the rate limits and my requests have not generated any errors. My application still works from a different IP so the application itself is not blocked.
I have followed the advice in the FAQ but I’m at a loss as to what is causing the problem. How do I find out from Twitter why they have blocked the IP?