diff --git a/isometric-park-fna/Simulation.cs b/isometric-park-fna/Simulation.cs
--- a/isometric-park-fna/Simulation.cs
+++ b/isometric-park-fna/Simulation.cs
@@ -441,6 +441,11 @@
 
                 int advancesToSimulate = (int)((this.Elapsed - this.lastAdvance) / millisecondsPerAdvance);
 
+                if (this.lastAdvance > this.Elapsed)
+                {
+                    Logging.Error(String.Format("Last Advance is ahead of Elapsed by {0} ms. This should basically never happen.", (this.lastAdvance - this.Elapsed)));
+                }
+
                 for (int i = 0; i < advancesToSimulate; i++)
                 {
                     this.advanceSimulation();
@@ -452,8 +457,8 @@
                     //it's t=125, we have 2.5 steps to simulate. However, we only want to simulate
                     //whole steps for simplicity's sake, so that means we'll simulate 2. But that means we've only simulated
                     //through t=120, so that's what we want to track in lastAdvance.
+                }
                     this.lastAdvance += advancesToSimulate * millisecondsPerAdvance;
-                }
             }
         }
     }