Hello,
I love your plugin showcase.
I always have using it as the standard shop.
But I have an error

Symptoms:
Showcases spawns too many items instead of one and you can even pick it up!

Error log:
There isn't one, but...

Error log when reloading the plugin using pail:

2012-01-14 19:30:40 [INFO] Can't find key disableMessage for translation!
2012-01-14 19:30:40 [WARNING] Could not properly handle event ITEM_SPAWN:
java.lang.IllegalAccessError: Synchronized code got accessed from another thread: java.awt.EventDispatchThread
	at org.bukkit.event.entity.EntityListener.onItemSpawn(EntityListener:0)
	at org.bukkit.plugin.java.JavaPluginLoader$73.execute(JavaPluginLoader.java:774)
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:58)
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:339)
	at org.bukkit.craftbukkit.event.CraftEventFactory.callItemSpawnEvent(CraftEventFactory.java:285)
	at net.minecraft.server.World.addEntity(World.java:889)
	at net.minecraft.server.World.addEntity(World.java:860)
	at org.bukkit.craftbukkit.CraftWorld.dropItem(CraftWorld.java:297)
	at org.bukkit.craftbukkit.CraftWorld.dropItemNaturally(CraftWorld.java:311)
	at com.narrowtux.showcase.ShowcaseItem.<init>(ShowcaseItem.java:62)
	at com.narrowtux.showcase.Showcase.load(Showcase.java:365)
	at com.narrowtux.showcase.Showcase.onEnable(Showcase.java:153)
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:188)
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:968)
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:280)
	at de.nofear13.craftbukkituptodate.CraftBukkitUpToDateJPanel$ReloadButton.actionPerformed(CraftBukkitUpToDateJPanel.java:87)
	at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
	at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
	at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
	at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
	at com.jtattoo.plaf.BaseButtonListener.mouseReleased(BaseButtonListener.java:41)
	at java.awt.Component.processMouseEvent(Unknown Source)
	at javax.swing.JComponent.processMouseEvent(Unknown Source)
	at java.awt.Component.processEvent(Unknown Source)
	at java.awt.Container.processEvent(Unknown Source)
	at java.awt.Component.dispatchEventImpl(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
	at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
	at java.awt.Container.dispatchEventImpl(Unknown Source)
	at java.awt.Window.dispatchEventImpl(Unknown Source)
	at java.awt.Component.dispatchEvent(Unknown Source)
	at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
	at java.awt.EventQueue.access$000(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.awt.EventQueue$3.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.awt.EventQueue$4.run(Unknown Source)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
	at java.awt.EventQueue.dispatchEvent(Unknown Source)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
	at java.awt.EventDispatchThread.run(Unknown Source)
2012-01-14 19:30:40 [INFO] This error is logged only once: it could have occurred multiple times by now.
2012-01-14 19:30:41 [INFO] [Showcase] Registered type [basic] (0 items loaded)
2012-01-14 19:30:41 [INFO] [Showcase] Registered type [finite] (96 items loaded)
2012-01-14 19:30:41 [INFO] [Showcase] Registered type [infinite] (80 items loaded)
2012-01-14 19:30:41 [INFO] [Showcase] Registered type [exchange] (0 items loaded)
2012-01-14 19:30:41 [INFO] [Showcase] Registered type [tutorial] (0 items loaded)
2012-01-14 19:30:41 [INFO] [Showcase] version 0.7.9 has been enabled.
2012-01-14 19:31:05 [WARNING] Can't keep up! Did the system time change, or is the server overloaded?

I have win7 64bit, java 1.7 64bit, RB 1.0.1-R1.

Please help,
Thank you