im trying to mmmm "join,pack,paste,glue togther" or whatever word or frase you use to describe what im trying to do. im trying to put together 10 mpegs from website. im using ordix mpack pro v4.0 and it says it is not an valid mpeg file. the files are mpg's. but i have already "joined,pasted,glued" other mpg's with out a problem only these files. what could the problem be?