Error - clips on storyboard

I was able to import my avi video just fine. I can edit the clips all I like
but when I add them to the storyboard (by dragging or right-clicking) a big
red x appears. It'll let me hit play and it acts like it is playing the clip
except there is nothing there - no images or sound. If I right click for
properties it gives me all the correct imformation. What's going on & how do
I fix it?