The loss of synch in your digital video files is a common problem. The
source of the problem is the data rate that you have used when
compressing the dv files. DV files played from a CD have a much tougher
time of it than files played from the hard drive. The CD reader has
only one read head, it usually has a slower data throughput and a
smaller cache. If the computer has more than one data bus, the CD drive
is usually connected to the slower bus. When you play the DV files
through Director, the DV player is running as a guest application on
top of Director. The DV player has to share resources with Director and
so Director has to clear out memory space and allocate screen real
estate for the DV player. If your movie is asking for assets from the
CD at the same time as the DV file is playing, there will be a conflict
for the use of the one read head on the CD reader.
You will need to lower the data rate of the DV file. You'll have to try
a number of different rates to find one that works well in most cases.
You may also need to optimize the playback of your movie to allow for a
free flow of data from the CD. You may also need to change the way that
you are addressing the DV file in the score to allow for the DV player
to start up without problems.
There are a number of tech notes on working with digital video in
Director, you may find some additional useful information there.