Problems loading big movies

Hi guys,

I have a flash MX presentation organized in two levels.
The first swf movie is used to start the presentation and the others are loaded on the level 1 whenever the users selct a button on the navbar.

Many times when switching from a movie to another it happens that the player or the projector shows a previous frame or a wrong scene of the right movie for a while.

I use the loadmovienum to load swf.
Probably I missed some best pratic while designing the application.

Please help me to fix this problem.