Loading external swf

i am having a problem i will try an explain it as best i can, maybe someone can help.

I have a base flash movie with a movie clip instance in it called “animation” the base document loads an external file cardboard.swf into the movie “animation”. in the last frame of cardboard.swf the following actionscript is used to load a new movie in its place:

checkLoaded = function(){
_root.animation.loadMovie(“dnew.swf”);
}
intervalID = setInterval(checkLoaded, 800);
stop();

likewise the dnew.swf has similar actionscripting to load a different swf an so on and so forth. the end result I want is a loop of around 12 different movies.

the problem i am having is when viewing the base movie the first and second movies plan fine, the third movie loads but doesnt play right, it jumps back and forth between frames and doesn’t load the next movie.

anybody got an idea of whats going on?