I have the MPeg-4 plugin but i have several files that state they are Mpeg4 and I get no video in Studio 12.... Anyway to know what codec to use??? I would reall apprecuate the help on this as these are rare videos them on dvd. THANKS!

There are many different kinds of "mpeg4".  You may find that you need to convert the file into something that Studio *can* use.  One easy option is the "Super" package, which is a "friendly" front-end to some fairly sophisticated tools.

BittMann