I've ran into this problem a couple times so far. When viewing a webpage in firefox that has a video or ad that plays automatically, the video or automatic ad will start later when the phone is in my pocket locked. Even if I pause the video ad and then hit the home button to close the browser, it still does it. Additionally, it does it when backing out using the 'back' key next to the home key. It's almost like firefox is staying awake while the phone is locked for some reason. Anyone else experience this or know if it's browser related?