diff --git a/bundles/org.openhab.core.compat1x/src/main/java/org/openhab/model/item/binding/AbstractGenericBindingProvider.java b/bundles/org.openhab.core.compat1x/src/main/java/org/openhab/model/item/binding/AbstractGenericBindingProvider.java
index 412ab4030e..dd08c43cef 100644
--- a/bundles/org.openhab.core.compat1x/src/main/java/org/openhab/model/item/binding/AbstractGenericBindingProvider.java
+++ b/bundles/org.openhab.core.compat1x/src/main/java/org/openhab/model/item/binding/AbstractGenericBindingProvider.java
@@ -13,7 +13,6 @@ import java.util.Collection;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
-import java.util.WeakHashMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArraySet;
 
@@ -25,112 +24,132 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * <p>This abstract class serves as a basis for implementations of binding providers that retrieve binding
- * information from the items configuration file(s), i.e. they register as {@link BindingConfigReader}s.</p>
- * 
- * <p>This class takes care of tracking all changes in the binding config strings and makes sure that all
- * listeners are correctly notified of any change.<p>
- * 
+ * <p>
+ * This abstract class serves as a basis for implementations of binding providers that retrieve binding
+ * information from the items configuration file(s), i.e. they register as {@link BindingConfigReader}s.
+ * </p>
+ *
+ * <p>
+ * This class takes care of tracking all changes in the binding config strings and makes sure that all
+ * listeners are correctly notified of any change.
+ * <p>
+ *
  * @author Kai Kreuzer
  * @since 0.6.0
  *
  */
 public abstract class AbstractGenericBindingProvider implements BindingConfigReader, BindingProvider {
 
-	private static final Logger logger = LoggerFactory.getLogger(AbstractGenericBindingProvider.class);
+    private static final Logger logger = LoggerFactory.getLogger(AbstractGenericBindingProvider.class);
 
-	private Set<BindingChangeListener> listeners = new CopyOnWriteArraySet<BindingChangeListener>();
+    private Set<BindingChangeListener> listeners = new CopyOnWriteArraySet<BindingChangeListener>();
 
-	/** caches binding configurations. maps itemNames to {@link BindingConfig}s */
-	protected Map<String, BindingConfig> bindingConfigs = new ConcurrentHashMap<String, BindingConfig>(new WeakHashMap<String, BindingConfig>());
+    /** caches binding configurations. maps itemNames to {@link BindingConfig}s */
+    protected Map<String, BindingConfig> bindingConfigs = new ConcurrentHashMap<String, BindingConfig>();
 
-	/** 
-	 * stores information about the context of items. The map has this content
-	 * structure: context -> Set of Items
-	 */ 
-	protected Map<String, Set<Item>> contextMap = new ConcurrentHashMap<String, Set<Item>>();
-	
+    /**
+     * stores information about the context of items. The map has this content
+     * structure: context -> Set of Items
+     */
+    protected Map<String, Set<Item>> contextMap = new ConcurrentHashMap<String, Set<Item>>();
 
-	public AbstractGenericBindingProvider() {
-		super();
-	}
+    public AbstractGenericBindingProvider() {
+        super();
+    }
 
-	/**
-	 * {@inheritDoc}
-	 */
-	public void addBindingChangeListener(BindingChangeListener listener) {
-		listeners.add(listener);
-	}
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void addBindingChangeListener(BindingChangeListener listener) {
+        listeners.add(listener);
+    }
 
-	/**
-	 * {@inheritDoc}
-	 */
-	public void removeBindingChangeListener(BindingChangeListener listener) {
-		listeners.remove(listener);
-	}
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void removeBindingChangeListener(BindingChangeListener listener) {
+        listeners.remove(listener);
+    }
 
-	/**
-	 * {@inheritDoc}
-	 */
-	public void processBindingConfiguration(String context, Item item, String bindingConfig) throws BindingConfigParseException {
-		Set<Item> items = contextMap.get(context);
-		if (items==null) {
-			items = new HashSet<Item>();
-			contextMap.put(context, items);
-		}
-			
-		items.add(item);
-	}
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void processBindingConfiguration(String context, Item item, String bindingConfig)
+            throws BindingConfigParseException {
+        if (context == null) {
+            throw new BindingConfigParseException("null context is not permitted for item " + item.getName());
+        }
+        synchronized (contextMap) {
+            Set<Item> items = contextMap.get(context);
+            if (items == null) {
+                items = new HashSet<Item>();
+                contextMap.put(context, items);
+            }
+            items.add(item);
+        }
+    }
 
-	/**
-	 * {@inheritDoc}
-	 */
-	public void removeConfigurations(String context) {
-		Set<Item> items = contextMap.get(context);
-		if(items!=null) {
-			for(Item item : items) {
-				// we remove all binding configurations for all items
-				bindingConfigs.remove(item.getName());
-				notifyListeners(item);
-			}
-			contextMap.remove(context);
-		}
-	}
-	
-	protected void addBindingConfig(Item item, BindingConfig config) {
-		bindingConfigs.put(item.getName(), config);
-		notifyListeners(item);
-	}
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void removeConfigurations(String context) {
+        Set<Item> items = null;
+        synchronized (contextMap) {
+            items = contextMap.get(context);
+            if (items != null) {
+                contextMap.remove(context);
+            }
+        }
+        if (items != null) {
+            for (Item item : items) {
+                // we remove all binding configurations for all items
+                bindingConfigs.remove(item.getName());
+                notifyListeners(item);
+            }
+        }
+    }
 
-	private void notifyListeners(Item item) {
-		for (BindingChangeListener listener : listeners) {
+    protected void addBindingConfig(Item item, BindingConfig config) {
+        bindingConfigs.put(item.getName(), config);
+        notifyListeners(item);
+    }
+
+    private void notifyListeners(Item item) {
+        for (BindingChangeListener listener : listeners) {
             try {
                 listener.bindingChanged(this, item.getName());
             } catch (Exception e) {
                 logger.error("Binding " + listener.getClass().getName() + " threw an exception: ", e);
             }
-		}
-	}
-	
-	/**
-	 * @{inheritDoc}
-	 */
-	public boolean providesBindingFor(String itemName) {
-		return bindingConfigs.get(itemName) != null;
-	}
-	
-	/**
-	 * @{inheritDoc}
-	 */
-	public boolean providesBinding() {
-		return !bindingConfigs.isEmpty();
-	}
-	
-	/**
-	 * {@inheritDoc}
-	 */
-	public Collection<String> getItemNames() {
-		return new ArrayList<String>(bindingConfigs.keySet());
-	}	
+        }
+    }
+
+    /**
+     * @{inheritDoc}
+     */
+    @Override
+    public boolean providesBindingFor(String itemName) {
+        return bindingConfigs.get(itemName) != null;
+    }
+
+    /**
+     * @{inheritDoc}
+     */
+    @Override
+    public boolean providesBinding() {
+        return !bindingConfigs.isEmpty();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Collection<String> getItemNames() {
+        return new ArrayList<String>(bindingConfigs.keySet());
+    }
 
 }
\ No newline at end of file