diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CDocumentProvider.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CDocumentProvider.java
index 7bb6e85c2b4..1239e7460f9 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CDocumentProvider.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CDocumentProvider.java
@@ -73,7 +73,6 @@ import org.eclipse.cdt.internal.core.model.IBufferFactory;
 import org.eclipse.cdt.internal.ui.CFileElementWorkingCopy;
 import org.eclipse.cdt.internal.ui.CPluginImages;
 import org.eclipse.cdt.internal.ui.text.IProblemRequestorExtension;
-import org.eclipse.cdt.internal.ui.util.ExternalEditorInput;
 
 /**
  * CDocumentProvider2
@@ -862,7 +861,7 @@ public class CDocumentProvider extends TextFileDocumentProvider {
 			tuInfo.fModel= new ExternalSearchAnnotationModel(markerResource, storage);
 			IAnnotationModel fileBufferAnnotationModel= tuInfo.fTextFileBuffer.getAnnotationModel();
 			if (fileBufferAnnotationModel != null) {
-				((AnnotationModel)tuInfo.fModel).addAnnotationModel("secondaryModel", fileBufferAnnotationModel); //$NON-NLS-1$
+				((AnnotationModel)tuInfo.fModel).addAnnotationModel("fileBufferModel", fileBufferAnnotationModel); //$NON-NLS-1$
 			}
 			tuInfo.fCachedReadOnlyState= true;
 		}
@@ -883,10 +882,14 @@ public class CDocumentProvider extends TextFileDocumentProvider {
 	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#isReadOnly(java.lang.Object)
 	 */
 	public boolean isReadOnly(Object element) {
-		// external editor input must not be modified
+		// external translation unit must not be modified
 		// because of missing functionality in CFileElementWorkingCopy
-		if (element instanceof ExternalEditorInput) {
-			return true;
+		FileInfo info= getFileInfo(element);
+		if (info instanceof TranslationUnitInfo) {
+			TranslationUnitInfo tuInfo= (TranslationUnitInfo)info;
+			if (tuInfo.fCopy instanceof CFileElementWorkingCopy) {
+				return true;
+			}
 		}
 		return super.isReadOnly(element);
 	}
@@ -895,10 +898,14 @@ public class CDocumentProvider extends TextFileDocumentProvider {
 	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#isModifiable(java.lang.Object)
 	 */
 	public boolean isModifiable(Object element) {
-		// external editor input must not be modified
+		// external translation unit must not be modified
 		// because of missing functionality in CFileElementWorkingCopy
-		if (element instanceof ExternalEditorInput) {
-			return false;
+		FileInfo info= getFileInfo(element);
+		if (info instanceof TranslationUnitInfo) {
+			TranslationUnitInfo tuInfo= (TranslationUnitInfo)info;
+			if (tuInfo.fCopy instanceof CFileElementWorkingCopy) {
+				return false;
+			}
 		}
 		return super.isModifiable(element);
 	}
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/ExternalSearchDocumentProvider.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/ExternalSearchDocumentProvider.java
index 0b2d66edafa..e6365b9f670 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/ExternalSearchDocumentProvider.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/ExternalSearchDocumentProvider.java
@@ -23,24 +23,38 @@ import org.eclipse.jface.text.source.IAnnotationModel;
 import org.eclipse.ui.IPathEditorInput;
 import org.eclipse.ui.IStorageEditorInput;
 import org.eclipse.ui.editors.text.ILocationProvider;
+import org.eclipse.ui.editors.text.TextFileDocumentProvider;
 
 import org.eclipse.cdt.core.resources.FileStorage;
 import org.eclipse.cdt.ui.CUIPlugin;
 
 import org.eclipse.cdt.internal.ui.util.ExternalEditorInput;
 
-public class ExternalSearchDocumentProvider extends CStorageDocumentProvider {
+public class ExternalSearchDocumentProvider extends TextFileDocumentProvider {
 	
-	/** Location attribute for breakpoints. See <code>ICBreakpoint.SOURCE_HANDLE</code> */
-	private static final String DEBUG_SOURCE_HANDLE = "org.eclipse.cdt.debug.core.sourceHandle"; //$NON-NLS-1$	
-
-	public ExternalSearchDocumentProvider(){
-		super();
+	public ExternalSearchDocumentProvider() {
+		super(new CStorageDocumentProvider());
 	}
 
 	/*
-	 * @see org.eclipse.ui.editors.text.StorageDocumentProvider#createAnnotationModel(java.lang.Object)
+	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createFileInfo(java.lang.Object)
 	 */
+	protected FileInfo createFileInfo(Object element) throws CoreException {
+		final FileInfo info= super.createFileInfo(element);
+		if (info.fModel == null) {
+			info.fModel= createAnnotationModel(element);
+			if (info.fModel != null) {
+				IAnnotationModel fileBufferAnnotationModel= info.fTextFileBuffer.getAnnotationModel();
+				if (fileBufferAnnotationModel != null) {
+					((AnnotationModel)info.fModel).addAnnotationModel("fileBufferModel", fileBufferAnnotationModel); //$NON-NLS-1$
+				}
+				setUpSynchronization(info);
+			}
+		}
+		return info;
+	}
+
+
 	protected IAnnotationModel createAnnotationModel(Object element) throws CoreException {
 		if (element instanceof ExternalEditorInput) {
 			return createExternalSearchAnnotationModel((ExternalEditorInput)element);
@@ -65,7 +79,7 @@ public class ExternalSearchDocumentProvider extends CStorageDocumentProvider {
 				return createExternalSearchAnnotationModel(storage, null);
 			}
 		}
-		return super.createAnnotationModel(element);
+		return null;
 	}
 
 	/**
@@ -96,8 +110,6 @@ public class ExternalSearchDocumentProvider extends CStorageDocumentProvider {
 			markerResource= CUIPlugin.getWorkspace().getRoot();
 			model = new ExternalSearchAnnotationModel(markerResource, storage, IResource.DEPTH_ONE);
 		}
-		// attach annotation model for C breakpoints
-		model.addAnnotationModel("debugMarkerModel", new ExternalSearchAnnotationModel(markerResource, storage, IResource.DEPTH_ZERO, DEBUG_SOURCE_HANDLE)); //$NON-NLS-1$
 		return model;
 	}