>http://www.dailymail.co.uk/news/worldnews/article-1185454/Stewardess-plane-appears-leaking-Shocking-picture-mid-air-fuel-leak-passenger-jet.html

I've seen videos on youtube and flightlevel350 that show the pilots actually releasing fuel out from that area of the wing (for emergency landings or other reasons)...

so... wonder if that part of the wing that allows them to release the fuel had a faulty valve but didn't show that as a problem in the cockpit?