Testing loaded movies

This loading jpegs thing into a main movie is drivng me nuts! Everyone said that you need to load the jpeg or swf into an empty movie clip and then simly build your preloaded from the emptymove clip. I have set up a couple of trace actions to see the bytes loaded and total bytes and it does the weirdest thing. It first reads 4 and then reads the correct amount of bytes. What is “4”??? Needless to say that screw up everything if it can’t read the correct info the first time…I can send the fla if anyone is interested in the problem…

Thanks in advance…