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.
Your iPod software can be out of date. All you have to do is to select restore iPod to factory defaults either in the iTunes program or on the iPod itself. This will restore the iPod to the original factory condition. A word of caution is that you will loose all of your songs as they will be erased. If your iPod is still not syncing with iTunes on your PC or mac, then I suggest rebooting both the PC and iPod with the usb plug disconnected. Once the PC is back on and completely booted up, plug in the usb cord on the iPod and iTunes should pop up and you should be able to sync your iPod to iTunes Try to reboot the iPod and PC a few times if necessary, it should work.