406 Not Acceptable on Filter Stream



I performed the following request:

POST https://stream.twitter.com/1.1/statuses/filter.json HTTP/1.1
Authorization: OAuth oauth_consumer_key="x",oauth_nonce="x",oauth_signature_method="HMAC-SHA1",oauth_timestamp="1373607988",oauth_token="x",oauth_version="1.0",oauth_signature="x"
User-Agent: My Agent
Content-Type: x-www-form-urlencoded
Host: stream.twitter.com
Content-Length: 13
Connection: Keep-Alive


And received the following response:

HTTP/1.1 406 Not Acceptable
Content-Type: text/html
Content-Length: 83

No filter parameters found. Expect at least one parameter: follow track locations



Clearly, the track parameter is provided. Any ideas on what could be causing the problem?


Took the circuitous route, but got an answer: https://dev.twitter.com/issues/1171

Needed to change my Content-Type to application/x-www-form-urlencoded.