If you're talking about that huge ass big blue box in the corner of your screen that is WAAAYYYY more than one pixel stuck. Thats a whole group or sector or what ever they call it. Its not "dead" though, if it were, it would be black. When they're a color, its concidered "stuck", but either way, take that back. And yes, it should be covered.
That's weird. A lot more than just one stuck pixel as another poster said. Try the pixel excorsizing thing but it looks like it'll need to be returned. Is it there with all backgrounds?
If it looks that way all the time (in other words not just in Safari) then, as has been stated above, it is certainly more than a single pixel and it should be taken care of by Apple. If it is only in Safari that is another issue altogether.