I use video in presentations and it is jerky when it plays. This started
suddenly about six months ago for no apparent reason.

I am running XP sp2, 512mb on a Lattitude D610

I used the Performance tool in XP and everytime the video jerked the paging
rate was all the way to the top of the scale. I have found that replaying
the video eliminates the jerking, so that would indicate a lower paging rate
because much of the video is already buffered.

AHA, thought I... more memory will solve the problem, so I bought 2GB on
sale, put it in, and it behaves EXACTLY the same way.

With plenty of memory and all the default media player settings, why am I
still paging so much?