Trouble with video playback

I am using Adobe Premiere 12.0.

I will cut my clip and then put it on the timeline.  However, when I click play, the video will be showing the uncut clip while the audio is cut.  There are parts of the video that glitch but they glitch at the same time each time; it is not random.  It is just a plain video with no effects or anything.  It is not like I am trying to overload my system.

Things I have tried:

Restarting the program and my computer

Reducing playback resolution

Turn off High Quality Playback

Changed Video Renderer to GPU Acceleration

I am running it on a Dell XPS with 8GB RAM and have about 13GB of free space on my hard drive.  

Please help!