Preview/Full Screen Viewer No Video

Just bought Family Movie Creator from Magix, looks great. But when I import my AVI and wmv videos to the editor, I can see the still frames throughout the video down in the editor.

The big preview window (and full screen too) doesn't show the video when its playing, it displays just black, no video. It shows that it is playing though. Anyone know what is going on? 

This is my first time using the program, I'm probably missing something!