How come on Sony Vegas 7.0 when i try to render a video, it only renders a couple seconds and thats it? wtf?

when i press render as, i save it and i press render..then a dialog box pops up and it says that percentage left and it says 100%, and once it goes past 00:06 seconds it says rendering is over, but it didnt render... and its like a 2:30 video... soo 00:06 sec its good..How come on Sony Vegas 7.0 when i try to render a video, it only renders a couple seconds and thats it? wtf?
Hi


For the best possible advice, I highly recommend you contact your local supplier or the Manufacturer....