Potion effects are properly removed on join and leave/death.

resources/plugin.yml

@@ -1,7 +1,7 @@
 name: MobArena
 author: garbagemule
 main: com.garbagemule.MobArena.MobArena
-version: 0.94.4.56
+version: 0.94.4.57
 softdepend: [Spout,MultiVerse,XcraftGate,Towny,Heroes,MagicSpells,Vault]
 commands:
     ma:

src/com/garbagemule/MobArena/ArenaImpl.java

@@ -684,7 +684,7 @@ public class ArenaImpl implements Arena
     
     private void removePotionEffects(Player p) {
         for (PotionEffect effect : p.getActivePotionEffects()) {
-            p.removePotionEffect(effect.getType());
+            p.addPotionEffect(new PotionEffect(effect.getType(), 0, 0), true);
         }
     }