Hi Kevin,
Depending on how your spatial model is configured (size distributions, primary vs. secondary groups, etc…) it is possible that you will end up with different results between spatial and non spatial simulations. The most likely cause would be some kind of spatial constraint in the way some transitions are spreading, or some error in configuration (for example in the assignment of transitions to primary vs. secondary groups). Without seeing your specific configuration it would be hard to say for sure. A good approach to diagnosing potential problems is to compare the expected area transitioning for each transition type (sum product [area by state]x[probability by state] at timestep t-1) vs. actual area transitioning at timestep t. If you see large differences for some transition types this may help you find out which aspects of your model configuration may have problems or at least be leading to counter intuitive results.
Regards,
Leonardo