remove your links from here that is the quickest way to lose your vbulletin..as there are many spies who tell on members. I have also update the xml to 3.7.3 and posted. I used both links and see what you mean am looking into it.
I can not dupliacte your error I made the theme default cleared all cookies,cache,flushdns,rebooted..and still no errors there must be something that was edited or plugin installed, modification added. I would have to look in the admincp to further diagnos the problem or you should have someone as its not on my end sorry.