What model of camcorder is your video coming from and what is the video's resolution and format?
This is most commonly seen with non-camcorder video that was recorded with a variable frame rate.
The footage actually came from my GoPro camera. 1080p at 24 frames per second. I shouldn't be having any trouble with that.
Some GoPros record in a variable frame rate. GoPro provides software called "GoPro Studio" to change that to fixed a frame rate for compatibility with common video editing software like Premier Elements.