Here is a quick to on how to fix issue with audio losing sync on Sony Vegas. We all know about matching your projects settings. You know the source to the Vegas project to the render settings. But here is one thing you guys will find useful.
When you put a title of graphic of some sort into your project its default setting is about 5 seconds and you usually drag is through out your project. This can through the sync of just a bit. What you should do instead is to complete your project then enter the text or graphic last. Once you put it in right click on it go to edit generated media and change the duration to the link of the project.