Most likely the problem is the software you are using to play the movie.
You are likely using Windows Media Player, which is a resource hog.
Use a different program to play the movie.
If you don't have another program, try this one:
I love my SD600! My only issue is that when I use it to shoot short videos (mainly of my 17-month-old daughter), the picture is great but the audio does not match the timing of the video! (Like a bad "Kung Fu" movie!! LOL)
Has anyone heard of this issue? I recommended the camera to my mom, she bought it and I have the same problem using hers. Is it the camera or my computer?
Any advice is much appreciated!