Rendering/Publishing in Sony Vegas 9?

[Gdnhjf]

I clicked File>Render as.. and then saved it to my desktop as an .avi format. whenever I do this, it starts rendering my video from the credits at the end, instead of from the beginning of my video. It publishes the video as only the 20 second credits. Why can't I render the entire video? What do I need to do? I do the exact same thing all the video tutorials do, when they do it, it works fine, but for me, it wont start at the beginning of the video. I have tried rewinding the the beginning and repeating with no success