Audio out of sync only in browser

I have an animation that is in sync on the timeline and when exported and played in the flash player it is still in sync. When embeded in a web page the animation is slower and it goes out of sync. I have a loader on it so that it doesn’t play until its all loaded, which I only added because I thought it might fix the problem, but it doesn’t.

The animation is set to 30fps. Does 30fps not work in a browser? Help a noob.

To sum it up:
In Flash (on timeline): In Sync
Standalone Flash player: In Sync
Embeded in browser: Not in Sync

Gracias