Human Factor - Physics experiments

After spending a great deal of time on configuring the Ode engine, I've managed to correctly place objects into the world that it represents. The problem is, however, that the objects do not interact as I intended them to do. From the screenshot you can see that the bomb which was placed on the back of the truck is now heading in full speed away from it. When you look at the ground, you will also see that there are som problems with the 3DS conversion I am doing. It looks as if the ground is broken somehow.