diff --git a/core/src/net/sf/openrocket/aerodynamics/AbstractAerodynamicCalculator.java b/core/src/net/sf/openrocket/aerodynamics/AbstractAerodynamicCalculator.java
index 1fb739407..978fd0900 100644
--- a/core/src/net/sf/openrocket/aerodynamics/AbstractAerodynamicCalculator.java
+++ b/core/src/net/sf/openrocket/aerodynamics/AbstractAerodynamicCalculator.java
@@ -4,6 +4,7 @@ import java.util.Map;
 
 import net.sf.openrocket.rocketcomponent.FlightConfiguration;
 import net.sf.openrocket.rocketcomponent.RocketComponent;
+import net.sf.openrocket.util.MathUtil;
 import net.sf.openrocket.util.Coordinate;
 
 
@@ -62,7 +63,7 @@ public abstract class AbstractAerodynamicCalculator implements AerodynamicCalcul
 		for (int i = 0; i < DIVISIONS; i++) {
 			cond.setTheta(2 * Math.PI * i / DIVISIONS);
 			cp = getCP(configuration, cond, warnings);
-			if (cp.x < worst.x) {
+			if ((cp.weight > MathUtil.EPSILON) && (cp.x < worst.x)) {
 				worst = cp;
 				theta = cond.getTheta();
 			}
diff --git a/swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java b/swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java
index ca06de076..ff9f377ea 100644
--- a/swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java
+++ b/swing/src/net/sf/openrocket/gui/scalefigure/RocketPanel.java
@@ -592,7 +592,7 @@ public class RocketPanel extends JPanel implements TreeSelectionListener, Change
 
 		cg = MassCalculator.calculateLaunch( curConfig).getCM();
 
-		if (cp.weight > MassCalculator.MIN_MASS){
+		if (cp.weight > MathUtil.EPSILON){
 			cpx = cp.x;
 		}else{
 			cpx = Double.NaN;