diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/LanguageMappingStore.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/LanguageMappingStore.java
index f59c7b54ec8..fb3b7f9d19f 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/LanguageMappingStore.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/LanguageMappingStore.java
@@ -163,7 +163,6 @@ public class LanguageMappingStore {
 		Iterator entries = contentTypeMappings.entrySet().iterator();
 		while (entries.hasNext()) {
 			Entry entry = (Entry) entries.next();
-			Element mapping = document.createElement(CONTENT_TYPE_MAPPING);
 			
 			String configuration = (String) entry.getKey();
 			Iterator contentTypeEntries = ((Map) entry.getValue()).entrySet().iterator();
@@ -172,6 +171,7 @@ public class LanguageMappingStore {
 				String contentType = (String) configurationEntry.getKey();
 				String language = (String) configurationEntry.getValue();
 				
+				Element mapping = document.createElement(CONTENT_TYPE_MAPPING);
 				mapping.setAttribute(ATTRIBUTE_CONTENT_TYPE, contentType);
 				mapping.setAttribute(ATTRIBUTE_CONFIGURATION, configuration);
 				mapping.setAttribute(ATTRIBUTE_LANGUAGE, language);
@@ -194,7 +194,7 @@ public class LanguageMappingStore {
 			serializer.transform(source, result);
 			String encodedMappings = buffer.getBuffer().toString();
 			
-			Preferences node = CCorePlugin.getDefault().getPluginPreferences();;
+			Preferences node = CCorePlugin.getDefault().getPluginPreferences();
 			node.setValue(CCorePreferenceConstants.WORKSPACE_LANGUAGE_MAPPINGS, encodedMappings);
 			CCorePlugin.getDefault().savePluginPreferences();
 		} catch (ParserConfigurationException e) {
@@ -205,7 +205,7 @@ public class LanguageMappingStore {
 	}
 	
 	public WorkspaceLanguageConfiguration decodeWorkspaceMappings() throws CoreException {
-		Preferences node = CCorePlugin.getDefault().getPluginPreferences();;
+		Preferences node = CCorePlugin.getDefault().getPluginPreferences();
 		String encodedMappings = node.getString(CCorePreferenceConstants.WORKSPACE_LANGUAGE_MAPPINGS);
 		WorkspaceLanguageConfiguration config = new WorkspaceLanguageConfiguration();
 		
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/language/ProjectLanguageMappingPropertyPage.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/language/ProjectLanguageMappingPropertyPage.java
index 95c8d31b24d..5abc293076c 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/language/ProjectLanguageMappingPropertyPage.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/language/ProjectLanguageMappingPropertyPage.java
@@ -20,6 +20,7 @@ import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Group;
 import org.eclipse.ui.dialogs.PropertyPage;
 
@@ -70,10 +71,30 @@ public class ProjectLanguageMappingPropertyPage extends PropertyPage {
 		fetchWorkspaceMappings();
 		fInheritedMappingWidget.createContents(group, null);
 		fInheritedMappingsChangeListener = new ILanguageMappingChangeListener() {
-			public void handleLanguageMappingChangeEvent(ILanguageMappingChangeEvent event) {
+			public void handleLanguageMappingChangeEvent(final ILanguageMappingChangeEvent event) {
 				if (event.getType() == ILanguageMappingChangeEvent.TYPE_WORKSPACE) {
-					fetchWorkspaceMappings();
-					fInheritedMappingWidget.refreshMappings();
+					if (ProjectLanguageMappingPropertyPage.this.isControlCreated()) {
+						Display.getDefault().asyncExec(new Runnable() {
+							public void run() {
+								if (!ProjectLanguageMappingPropertyPage.this.getControl().isDisposed()) {
+									fetchWorkspaceMappings();
+									fInheritedMappingWidget.refreshMappings();
+								}
+							}
+						});
+					}
+				}
+				else if (event.getType() == ILanguageMappingChangeEvent.TYPE_PROJECT) {
+					if (ProjectLanguageMappingPropertyPage.this.isControlCreated()) {
+						Display.getDefault().asyncExec(new Runnable() {
+							public void run() {
+								if (!ProjectLanguageMappingPropertyPage.this.getControl().isDisposed()) {
+									fetchMappings(event.getProject());
+									fMappingWidget.refreshMappings();
+								}
+							}
+						});
+					}
 				}
 			}
 		};