windows movie maker not in sync compared to media player.

i use movie maker to make amv's, because i'm an idiotic weaboo. but, since the beginning, i've noticed that whenever i saved my project, whenever i opened it up in media player {or anything else}, it was a hair of a second off compared to what my project was in movie maker. this wasn't too big of a deal; just meant that i had to save it constantly to check it in media player. but, now i am creating another amv, but this time, the music is off significantly. when played in media player, the music and the video are synced. but in movie maker, the audio plays faster than the video. i have used the same music type {mp3} and the same video files for this amv as i have in the past. anyone have an answer?