That's a pretty big drop from the practice tests. Did you take the GMAT Prep tests? Those tend to be those most accurate, since they are made by the GMAC itself. If you scored in the upper 500s on one of those, I'd be pretty shocked if you got a 480.
Okay, anyway, what you need to do is pinpoint what you did wrong in your study. It's a little tough with the "on demand" class because, although you have someone presenting material to you, you don't get the study tips and personal interaction you'd get from a live course.
The biggest issue for people is usually that they did not spend enough time dissecting problems. Admittedly, the Veritas materials contain lots of questions. Don't feel like you have to do all of them. It's all about quality over quantity. So, spend 20 minutes picking apart that question that gave you trouble; you'll understand the same concept the next time. For verbal, pick apart the WRONG answers as well as the right answer - you'll learn 5x as much. I like to give my students two rules to live by when studying:
1. If I gave you that same problem to do next week, you'd get it right almost instantly, and
2. You'd be able to teach the problem to me.
In my live classes, I even do that sometimes - pick a problem from last week's homework and ask for volunteers to explain it. I then (nicely, of course) mention to the folks who didn't volunteer that they need to study more. :)
Hope this helps!
Jim S. - Veritas Prep GMAT Instructor (Los Angeles, CA)