Using video in MX

Hi there!
I am experimenting with video in flash mx.
I’ve first tried with a 90 sec. video of mine that took ages to be imported(reducing quality of 50%).
When it came to export the whole flash movie it nearly crashed my machine!
I then tried with a smaller video(45 sec) again reducing quality.
It worked better, still takes long time to export as swf.
The problem now is that the video and its audio are totally out of sinc!(I’ve built two simple play and stop buttons with some actionscript).
I mention that i am using the video inside a movie clip.
If anyone can give me some tips it’ll be great.
Cheers…