Better trust minwah on this one, it's much harder to do then you would think. I had that option in dk early on and it turned out to be "breaking" a lot of other things, causing some systems to crash. I ended up having to take out the option.
The solution I found was to check to see if a key is pressed before running the movie routine. So bascially you can't skip a movie once it's started, but if you are holding down a key during bootup it'll skip it. You might wanna try fixing it that way, saves a lot of headaches.