Vegas pro 8.0 rendering problem, not the same as Johunn's

[Cooto3s]

Well I recently got this thing, and im very very new too it, infact this is my first movie that I've ever made.
I wanted to render it too .WMV but it doesnt work, I've tried all the formats but it doesnt work! It takes like 2 seconds to render the movie (which is 11mins long) and when I try to watch it its all black and no sound or anything.

What's wrong??

EDIT: Well to be honest it's my second video, I made a 3mins video yesterday, where I also noticed that I couldnt render it too WMV, but only MPG, which I cant now.

[Paul LS]

To export the movie are you going File>Render As?
Also by default the "Render loop region only" is checked in the export window. Do you have the loop region (the bar above the timeline with yellow handles each end) over the section you want to export, if the loop region is fully collapsed it will export the complete timeline but if you have it extended just to cover a second or two it will only export this.