This was a recent issue I dealt with that one hand might seem obvious, but actually took a big of digging to trouble shoot.
If you have set up your blog or RSS feed to funnel into Facebook, you may have run into this once or twice. What we’re talking about is your RSS feed posts showing up in Facebook more than once upon posting. The reason might vary for how you setup your accounts but I thought it best to offer a few suggestions for you to troubleshoot.
Hopefully one of these will lead you in the right direction:
1- Check your WordPress plugins, make sure there isn’t one that might be doubling up or sending out a post from your feed into Facebook. If one looks suspicious, you might try deactivating it until you can test this against your accounts.
2- Are you using Facebook’s “RSS Graffiti” plugin? Check the settings to make sure you didn’t set up 2 channels by accident that post back to your Facebook page
3- Lastly but not least (and for the record the one I eventually tracked the issue down to)
Are you using http://twitterfeed.com/ to autopost your RSS feeds into Facebook?
Make sure you login and check your settings. http://twitterfeed.com/ allows you to autopost your RSS feed back into Facebook thru Twitterfeed. It’s a great solution, however it’s quite possible that 1 of 2 things occurred.
1- you accidentally created the service twice (of which it will hit Facebook 2X on every post)
2- you created 2 accounts (forgetting about the original you set up) which are also hitting Facebook 2x Continue reading Facebook Posts are Posting Twice (or more) Issue?