This is a known issue that we are looking into. We do not have a permanent fix just yet, so in the meantime the best way to correct this is to manually delete the duplicating article in Dashboard.
You'll need to login to Dashboard > locate and select the duplicate article you wish to delete > click the 'X' next to the article title.
The duplicating article issue is due to the use of micro URLs. If your website uses a plugin that creates micro URLs, our system will read both the long and micro URLs as two separate articles. Even though the URLs possess the same content, it will post the article twice - once using the long URL and a second time with the micro.