I am getting the white screen too. The moment I run or drive the tractor it freezes (but can still hear things like walking or tractor driving). It was doing this on the original version and now on version .73
Perhaps you should try with some different video settings. I've set Area Density to flat because the rugged terrain vehicles create when driving makes it lag insanely after a while. It'll continue to lag for a while after setting it to flat, because it doesn't remove the ruggedness instantly but it will fade away in time.