After a kerfuffle on Twitter (and this here blog) over the possibility that Twitter broke its '@ reply' system, Twitter has responded saying it's working on the issue. "It's a bug. We should have a fix soon," a Twitter spokesperson told Gizmodo's Mat Honan.

When the Incidental Economist's Austin Frakt wrote about the issue, it wasn't clear there was a bug at all. When we experimented with it on Twitter.com, TweetDeck and the Twitter app for iPhone, we didn't see a problem on Twitter.com or Tweetdeck, but when putting a period in front of an '@ reply' using the iPhone app, the conversation did not show up as it should have. Twitter user Philip Bump confirmed the same issue in a Tweet from yesterday. 

But, after we posted our findings, Dan Diamond, who had discovered the issue with Frakt, pointed out the problem still persisted for him, sending us tweet conversations, like this one with @DailyBriefing that did not show up in his stream. "Note the coding here – this is coded as a reply, which means users can see the threaded conversation," he wrote to The Atlantic Wire in an email. "But it didn’t show up for me, despite following the Daily Briefing." A little back and forth over Twitter with Shoq Value, confirmed the problem was not limited to the app.

Not only has Twitter confirmed that there is indeed a bug, but Twitter User Rob Begbie told Honan he noticed the issue over a year ago, in January 2011, meaning it has nothing to do with the most recent Twitter redesign, which changed the way conversations work, making following them easier.