Like everything else, Flash handles buttons based on depth. If buttonA has a higher depth than buttonB - you will not be able to access buttonB (assuming it is completely covered by buttonA).
So, if you want to "disable" the rollOver effects on the video player, place a 'dummy' button over the entire video player (or portion you don't want affected by rollOver commands). Then, you can disable the hand cursor that appears over buttons by...
Now, the video player will be unaffected by any rollOver/rollOut commands. Next, place your movieClip controller you made
above the dummy button and you're good to go.