Flash loads image again after preload

I’m making a flv movie with dynamically loaded cuepoints (from xml).

On every cuepoint there should fade in an image (jpg) . The path to this image is sent with the cuepoints

To be sure an image is loaded before the cuepoint is passed, i’ve created a preloader that preloads 4 image from the xml before even starting the video.

After the video is started the preloader preloads the remaining images in the background.

All works well expect for 1 thing:

Flash does not seem to cache my preloaded images. In the bandwidthprofiler i can see that when a cuepoint passes, flash loads the preloaded images again.

My question is : why does flash reload the image while it is already preloaded ?

Thanks in advance!

myscript for preloading (works)

this.createEmptyMovieClip("plcontainer", "900"); 
plcontainer._visible = false;

plPic = String(myCuePic_arr.shift()); // example: "media/pictures/pic3.jpg"
plMovie = "preload_"+plCount;
myDepth = plcontainer.getNextHighestDepth();
plcontainer.createEmptyMovieClip(plMovie, myDepth);
my_mc.loadClip(plPic, ("plcontainer."+plMovie));
my_mc.loadMovie(plPic, ("plcontainer."+plMovie));

myScript for putting the image in place (works but loads the preloaded image again)

// get the path from the cuepoint info
var picPath = String(eventObject.info.cuePath); // example: "media/pictures/pic3.jpg"
loadMovie(picPath, "container");