One thing you can check easily.

If you open the Render Settings dialog (Render > Render Settings), and click the Firefly tab in the dialog, what happens if you uncheck Use Displacement Maps?

Displacement is the only thing I can think of off the top of my head that might be different. If you turn the displacement OFF in Render Settings it won't use them during Render. Then if your content looks OK after rendering with displacement OFF, there is something set too high in your materials, is pretty much all I can think of offhand.