Here's a screen of the code inserted:
As you can see it's right after the body tag and right before the yui JS.
I'm using the following scripts:
* vBulletin 3.8.5
* OpenX v2.8.6
* Photopost 7.03
* Reviewpost 5.1
* vBSEO 3.5.2
I've been looking for the leak / code but can't seem to find anything. Any help is appreciated.