This is occurring on this event page: http://www.roblox.com/sponsored/BLOXgiving
In the HTML for the page, there is no title tag which makes the tab look weird.
I don’t know if this is a bug, but the bar that moves under BLOXGiving and Games starts out under BLOXGiving and quickly moves to Games. I don’t know if that’s intentional but it doesn’t look like it.