diff --git a/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/compat/MCAccess.java b/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/compat/MCAccess.java
index 35d68299..5c180749 100644
--- a/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/compat/MCAccess.java
+++ b/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/compat/MCAccess.java
@@ -91,13 +91,13 @@ public interface MCAccess {
 	/**
 	 * 
 	 * @param player
-	 * @return Double.MIN_VALUE if not present.
+	 * @return Double.NEGATIVE_INFINITY if not present.
 	 */
 	public double getJumpAmplifier(Player player);
 	
 	/**
 	 * 
-	 * @return Double.MIN_VALUE if not present.
+	 * @return Double.NEGATIVE_INFINITY if not present.
 	 */
 	public double getFasterMovementAmplifier(Player player);
 
diff --git a/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/utilities/PotionUtil.java b/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/utilities/PotionUtil.java
index 3c6c48ca..fb304402 100644
--- a/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/utilities/PotionUtil.java
+++ b/NCPCompat/src/main/java/fr/neatmonster/nocheatplus/utilities/PotionUtil.java
@@ -17,14 +17,14 @@ public class PotionUtil {
 	 * Get amplifier for a potion effect.
 	 * @param player
 	 * @param type
-	 * @return Double.MIN_VALUE if not present, otherwise the maximal amplifier.
+	 * @return Double.NEGATIVE_INFINITY if not present, otherwise the maximal amplifier.
 	 */
 	public static final double getPotionEffectAmplifier(final Player player, final PotionEffectType type) {
-		if (!player.hasPotionEffect(type)) return Double.MIN_VALUE;
+		if (!player.hasPotionEffect(type)) return Double.NEGATIVE_INFINITY; // TODO: Might not win anything.
 		final Collection<PotionEffect> effects = player.getActivePotionEffects();
-		double max = Double.MIN_VALUE;
+		double max = Double.NEGATIVE_INFINITY;
 		for (final PotionEffect effect : effects){
-			if (effect.getType() == type){
+			if (effect.getType().equals(type)){
 				max = Math.max(max, effect.getAmplifier());
 			}
 		}
diff --git a/NCPCompatCB2511/src/main/java/fr/neatmonster/nocheatplus/compat/cb2511/MCAccessCB2511.java b/NCPCompatCB2511/src/main/java/fr/neatmonster/nocheatplus/compat/cb2511/MCAccessCB2511.java
index d08664ce..965420bd 100644
--- a/NCPCompatCB2511/src/main/java/fr/neatmonster/nocheatplus/compat/cb2511/MCAccessCB2511.java
+++ b/NCPCompatCB2511/src/main/java/fr/neatmonster/nocheatplus/compat/cb2511/MCAccessCB2511.java
@@ -111,14 +111,14 @@ public class MCAccessCB2511 implements MCAccess {
 		final net.minecraft.server.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 	
 		if (mcPlayer.hasEffect(MobEffectList.JUMP)) return mcPlayer.getEffect(MobEffectList.JUMP).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
 	public double getFasterMovementAmplifier(final Player player) {
 		final net.minecraft.server.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 		if (mcPlayer.hasEffect(MobEffectList.FASTER_MOVEMENT)) return mcPlayer.getEffect(MobEffectList.FASTER_MOVEMENT).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
diff --git a/NCPCompatCB2512/src/main/java/fr/neatmonster/nocheatplus/compat/cb2512/MCAccessCB2512.java b/NCPCompatCB2512/src/main/java/fr/neatmonster/nocheatplus/compat/cb2512/MCAccessCB2512.java
index d63c0310..9981426a 100644
--- a/NCPCompatCB2512/src/main/java/fr/neatmonster/nocheatplus/compat/cb2512/MCAccessCB2512.java
+++ b/NCPCompatCB2512/src/main/java/fr/neatmonster/nocheatplus/compat/cb2512/MCAccessCB2512.java
@@ -110,14 +110,14 @@ public class MCAccessCB2512 implements MCAccess{
 		final net.minecraft.server.v1_4_5.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 	
 		if (mcPlayer.hasEffect(MobEffectList.JUMP)) return mcPlayer.getEffect(MobEffectList.JUMP).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
 	public double getFasterMovementAmplifier(final Player player) {
 		final net.minecraft.server.v1_4_5.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 		if (mcPlayer.hasEffect(MobEffectList.FASTER_MOVEMENT)) return mcPlayer.getEffect(MobEffectList.FASTER_MOVEMENT).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
diff --git a/NCPCompatCB2545/src/main/java/fr/neatmonster/nocheatplus/compat/cb2545/MCAccessCB2545.java b/NCPCompatCB2545/src/main/java/fr/neatmonster/nocheatplus/compat/cb2545/MCAccessCB2545.java
index 748d0021..96b400c6 100644
--- a/NCPCompatCB2545/src/main/java/fr/neatmonster/nocheatplus/compat/cb2545/MCAccessCB2545.java
+++ b/NCPCompatCB2545/src/main/java/fr/neatmonster/nocheatplus/compat/cb2545/MCAccessCB2545.java
@@ -110,14 +110,14 @@ public class MCAccessCB2545 implements MCAccess{
 		final net.minecraft.server.v1_4_6.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 	
 		if (mcPlayer.hasEffect(MobEffectList.JUMP)) return mcPlayer.getEffect(MobEffectList.JUMP).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
 	public double getFasterMovementAmplifier(final Player player) {
 		final net.minecraft.server.v1_4_6.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 		if (mcPlayer.hasEffect(MobEffectList.FASTER_MOVEMENT)) return mcPlayer.getEffect(MobEffectList.FASTER_MOVEMENT).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
diff --git a/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/MCAccessCBDev.java b/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/MCAccessCBDev.java
index d1e9cbfd..8d74dd91 100644
--- a/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/MCAccessCBDev.java
+++ b/NCPCompatCBDev/src/main/java/fr/neatmonster/nocheatplus/compat/cbdev/MCAccessCBDev.java
@@ -111,14 +111,14 @@ public class MCAccessCBDev implements MCAccess{
 		final net.minecraft.server.v1_4_R1.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 	
 		if (mcPlayer.hasEffect(MobEffectList.JUMP)) return mcPlayer.getEffect(MobEffectList.JUMP).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
 	public double getFasterMovementAmplifier(final Player player) {
 		final net.minecraft.server.v1_4_R1.EntityPlayer mcPlayer = ((CraftPlayer) player).getHandle();
 		if (mcPlayer.hasEffect(MobEffectList.FASTER_MOVEMENT)) return mcPlayer.getEffect(MobEffectList.FASTER_MOVEMENT).getAmplifier();
-		else return Double.MIN_VALUE;
+		else return Double.NEGATIVE_INFINITY;
 	}
 
 	@Override
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/CreativeFly.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/CreativeFly.java
index a54fb51d..6bc71824 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/CreativeFly.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/CreativeFly.java
@@ -76,7 +76,7 @@ public class CreativeFly extends Check {
         final double speedModifier = mcAccess.getFasterMovementAmplifier(player);
         final double fSpeed;
         
-        if (speedModifier == Double.MIN_VALUE) fSpeed = 1D;
+        if (speedModifier == Double.NEGATIVE_INFINITY) fSpeed = 1D;
         else fSpeed = 1D + 0.2D * (speedModifier + 1D);
         
         final double limitH = cc.creativeFlyHorizontalSpeed / 100D * HORIZONTAL_SPEED * fSpeed;
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingListener.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingListener.java
index 63d564b8..538a02fa 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingListener.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/MovingListener.java
@@ -134,7 +134,7 @@ public class MovingListener extends CheckListener implements TickListener, IRemo
 	 */
 	public static final double getJumpAmplifier(final Player player) {
 		final double amplifier = NoCheatPlus.getMCAccess().getJumpAmplifier(player);
-		if (amplifier == Double.MIN_VALUE) return 0D;
+		if (amplifier == Double.NEGATIVE_INFINITY) return 0D;
 		else return 1D + amplifier;
 	}
 	
@@ -489,13 +489,18 @@ public class MovingListener extends CheckListener implements TickListener, IRemo
         moveInfo.set(player, from, to, cc.yOnGround);
           
         if (cc.debug) {
-			StringBuilder builder = new StringBuilder(250);
+			final StringBuilder builder = new StringBuilder(250);
 			final Location loc = player.getLocation();
-			builder.append(player.getName());
+			builder.append("\n" + player.getName());
 			builder.append(" " + from.getWorld().getName() + " " + StringUtil.fdec3.format(from.getX()) + (from.getX() == loc.getX() ? "" : ("(" + StringUtil.fdec3.format(loc.getX()) + ")")));
 			builder.append(", " + StringUtil.fdec3.format(from.getY()) + (from.getY() == loc.getY() ? "" : ("(" + StringUtil.fdec3.format(loc.getY()) + ")")));
 			builder.append(", " + StringUtil.fdec3.format(from.getZ()) + (from.getZ() == loc.getZ() ? "" : ("(" + StringUtil.fdec3.format(loc.getZ()) + ")")));
 			builder.append(" -> " + StringUtil.fdec3.format(to.getX()) + ", " + StringUtil.fdec3.format(to.getY()) + ", " + StringUtil.fdec3.format(to.getZ()));
+			final double jump = mcAccess.getJumpAmplifier(player);
+			final double speed = mcAccess.getFasterMovementAmplifier(player);
+			if (speed != Double.NEGATIVE_INFINITY || jump != Double.NEGATIVE_INFINITY){
+				builder.append(" (" + (speed != Double.NEGATIVE_INFINITY ? ("speed=" + speed) : "") + (jump != Double.NEGATIVE_INFINITY ? ("jump=" + jump) : "") + ")");
+			}
 			System.out.print(builder.toString());
 		}
         
@@ -514,8 +519,8 @@ public class MovingListener extends CheckListener implements TickListener, IRemo
         
 		// Potion effect "Jump".
 		final double jumpAmplifier = MovingListener.getJumpAmplifier(player);
-		if (jumpAmplifier > 0D && cc.debug) System.out.println(player.getName() + " Jump effect: " + jumpAmplifier);
 		if (jumpAmplifier > data.jumpAmplifier) data.jumpAmplifier = jumpAmplifier;
+		// TODO: same for speed (oncemedium is introduced).
 
         // Just try to estimate velocities over time. Not very precise, but works good enough most of the time. Do
         // general data modifications one for each event.
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
index 2b0235e3..7ca725eb 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java
@@ -536,7 +536,7 @@ public class SurvivalFly extends Check {
 		
 		// Speed amplifier.
 		final double speedAmplifier = mcAccess.getFasterMovementAmplifier(player);
-		if (speedAmplifier != Double.MIN_VALUE) hAllowedDistance *= 1.0D + 0.2D * (speedAmplifier + 1);
+		if (speedAmplifier != Double.NEGATIVE_INFINITY) hAllowedDistance *= 1.0D + 0.2D * (speedAmplifier + 1);
 		
 		return hAllowedDistance;
 	}