Small bug fixes.

ProtocolLib/src/com/comphenix/protocol/ProtocolLibrary.java

@@ -92,7 +92,7 @@ public class ProtocolLibrary extends JavaPlugin {
 	
 	private void createAsyncTask(Server server) {
 		try {
-			if (asyncPacketTask < 0)
+			if (asyncPacketTask >= 0)
 				throw new IllegalStateException("Async task has already been created");
 			
 			// Attempt to create task

ProtocolLib/src/com/comphenix/protocol/async/AsyncFilterManager.java

@@ -1,5 +1,6 @@
 package com.comphenix.protocol.async;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -177,7 +178,8 @@ public class AsyncFilterManager implements AsynchronousManager {
 	
 	@Override
 	public boolean hasAsynchronousListeners(PacketEvent packet) {
-		return getProcessingQueue(packet).getListener(packet.getPacketID()).size() > 0;
+		 Collection<?> list = getProcessingQueue(packet).getListener(packet.getPacketID());
+		 return list != null && list.size() > 0;
 	}
 	
 	/**

ProtocolLib/src/com/comphenix/protocol/async/AsyncListenerHandler.java

@@ -8,7 +8,6 @@ import org.bukkit.plugin.Plugin;
 import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.events.PacketEvent;
 import com.comphenix.protocol.events.PacketListener;
-import com.sun.org.apache.bcel.internal.generic.GETSTATIC;
 
 /**
  * Represents a handler for an asynchronous event.