My application authenticating user via web login, then save the needed credential and running API call in background task using cron. Sometimes the requests return a 401 unauthenticated error, and sometimes they don't. I readed on this issue: http://code.google.com/p/twitter-api/issues/detail?id=1052&can=1&q=%22401%22&colspec=ID%20Stars%20Type%20Status%20Priority%20Owner%20Summary%20Opened%20Modified%20Component
and the last post says: "This was the result of an issue with an experimental service we were testing. The bug should be resolved." Is it the issue of experimental service testing?? I'm not saving the log, but the error is around the "verify credentials" on the background task. And "get access token" on web login when redirecting back to my application.