That’d be either the font problem or the path problem…
If it is the font problem, embed the same font with the same linkage name into the library of your base movie… and test your movie to see if it does the trick…
If it is the path problem, you probably have _root.blahblah in your external movie file which needs to be changed to something like _level0.blahblah… If it is the path problem and you cannot fix it, please upload/post your code so that other people can help you… =)