A number of clients are still connecting on the deprecated Streaming API URLs. Be sure that your client is connecting to the documented /1/ statuses/* resources and not the unsupported /gardenhose, /spritzer, / shadow, /follow, /track, etc. resources. The old URLs have been unsupported for about 25 days and the rewrite rules may be removed at any time.
The original announcement: http://groups.google.com/group/twitter-development-talk/msg/46e5947fd0023a2d -John Kalucki http://twitter.com/jkalucki Services, Twitter Inc.