Sony Vegas 8 Freezing?

[AFT]

Ok I'm having a real problem with my Vegas. A few days ago I started a new project. I worked on it the first two day without a problem but the past few days, when I try to open the project, it goes really slow, taking more than a minute to open. I just forgot about it and kept on working, but today when I tried to open the project it started freezing. Down at the bottom left corner, after it finishes "opening project" it says "Building peaks" for a video I imported. It stays on that and never moves from 0%. At first I thought it was that I'd used up too much memory on my computer, so I deleted a few gigabytes of space I didn't need. I checked and even after that the project was still freezing.
What I don't understand is that this is the first time that happened to me. I've already spent months making another video on vegas, which is way more complex and takes up more memory than this new one, and it always works fine. What could it be? I imported 3 dvd's onto this new project and they take about 6gb each. Could it be that? Please, HELP!