Please Help! My model is getting cut when rendering

Hi there,
I’m rather new to Blender and with I was probably a bit ambitious with my first project. I put this sand castle onto the beach using Blender’s camera tracking and I set the movie as the background as you’d expect.

I did get this too work before (top image) but as I have recently come to redo this project I re-tracked everything and now when i set the film as the background it crops my model in half a set distance away from the camera. I have no idea how to fix this so please help!

I’m using Blender 2.65

The 3d view and the camera view both have clip start and clip end distances.
For the 3d view look in the properties panel (shortcut N) and for the camera, select it and look in its properties. Increase the clip end value to be large enough to fit the whole of your model