Every once in a while we get an email or a tweet from a reader who claims not being able to play YouTube videos in Mobile Safari, and asking for a fix. The answer I give is always the same: you probably installed a jailbreak tweak (likely ProTube) that conflicts with Safari and prevents you from watching YouTube videos in the browser.
Today, thanks to iDB reader J. Louis, we get to the bottom of this problem and find the real cause and the easy solution to fix it...