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

In any case, if this is so, make sure and deactivate at least one them

Some detective work:
Make sure you check your Facebook Apps to see if something sticks out that shouldn’t

A- Go to your personal profile
B- Right top corner: HOME–>ACCOUNT SETTINGS–APPS
C- Look thru the list of Apps being used

ALSO – remember that if you have multiple ADMINS (assigned to the problem page), one of the other ADMINS may have an APP or setting that is being funneled thru “their” account. You may have to log into their personal account, or have them do it to see if anything is setup on their end. For instance, if your personal account and their personal account are both using the “RSS Graffiti” plugin, then it may be triggering twice on the same Facebook Page.

Usually by trying all the above you can filter your way down into where the issue is occurring

Keywords:
– Posts appear twice
– Facebook posting more than once
– Facebook RSS feed appears twice
– Facebook RSS feed is doubling up