in the past day or so, “something” happened to my forum (http://www.toonbarn.com/forum) that causes it to display twice. The first version is the unwanted one: stretched to full screen width and without any of my site header. scroll down a bit and you’ll see our header and logo, and then the proper forum.
i know there were some forum plugin updates that i updated in the past two days or so, but didn’t know if that was related.
just as an update… i tried a new theme, new overlay, and disabling my forum plugins, but the weirdo display remained
another update!
it appears to be some sorta conflict with one of the many pieces of the “jetpack” plugin
hm. ok, now i’m stuck. if i disable the entire jetpack plugin, the message board forum displays normally. but if i try to disable the pieces of the plugin one by one, it remains in the double view. 
Go to the forum admin > Integration > Page and Permalink panel – look at the Theme Display Options and try turning on one of the top two one at a time.
The WP loop option fixed this for me – and is indeed something to do with the Jetpack update.
Not sure what though!
That would explain why we have had a rash of these lately. JetPack – in my personal opinion – is far more trouble than it is worth…
yeeup, that was it! I now have these two checked, and all seems well:
Limit forum display to within WP loop
Allow multiple loading of forum content
thanks guys!!
thanks for the update…. that latest update to jetpack sure is messing with things… we will try to get to the bottom of it…