video panel showing green clips and glitchy playback

My issue is that the video, whenever i add an effect or text, like if i do anything to edit the video, in my panel the video has a green thumbnail. after it shows this green thumbnail when i play it back it plays a little of the true clip(s) and then grabs like 3 other random clips usually about 3 or more frames of it, from somewhere else in the video and plays them in place of my video. My work ive done is just deleted! im not understanding whats wrong. Oh and im in adobe premiere pro cs6.0.3. Im actually like semi-new to this but i know this is no editing issue this is a program issue.