MovieClip Movement Stutters Upon Playing Sound

I have a MovieClip object (a basic shape) that moves across the screen back and forth. This movement works fine and is smooth. But, whenever I play a sound effect, then the object stops for a split second and then continues moving.

This is very confusing to me because I’ve programmed other very similar object translations with sound and yet never experienced this movement problem. I’m prepared to upload the code which shows this happening if necessary. However, I’m suspecting that I inadvertently changed some setting in my Flash CS3.

Any ideas on how I can solve this problem and have sound effects not affecting the smoothness of my MovieClip movements?