i have one of those problems nobody seems to have ;) I positioned the div #flash-header (which swfobject uses for the flash-movie) with a negative position like so:
The problem: The div has the right position (tested with colored background), as soon as i put the flash inside, the flash has an added "bottom margin" of 28px. (position of div stays -28px, flash "starts" 28px from bottom of div)
A workaround that works was to put another div (without absolute position) inside the positioned div and put the flash inside that div, but it would just be nice to get rid of that div ;-)