diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptor.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptor.java
index 6f7d72a64a2..21a5f3d0496 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptor.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptor.java
@@ -50,10 +50,10 @@ public class CDescriptor implements ICDescriptor {
 	private HashMap extMap = new HashMap(4);
 	private HashMap extInfoMap = new HashMap(4);
 		
-	private final String DESCRIPTION_FILE_NAME = ".cdtproject";
-	private final String PROJECT_DESCRIPTION = "cdtproject";
-	private final String PROJECT_EXTENSION = "extension";
-	private final String PROJECT_EXTENSION_ATTRIBUTE = "attribute";
+	final static String DESCRIPTION_FILE_NAME = ".cdtproject";
+	private final static String PROJECT_DESCRIPTION = "cdtproject";
+	private final static String PROJECT_EXTENSION = "extension";
+	private final static String PROJECT_EXTENSION_ATTRIBUTE = "attribute";
 
 	private boolean fDirty;
 
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptorManager.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptorManager.java
index 27c6bf32cc4..ba65ce6cd17 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptorManager.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/CDescriptorManager.java
@@ -11,10 +11,12 @@ import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.ICDescriptor;
 import org.eclipse.cdt.core.ICExtension;
 import org.eclipse.cdt.core.ICExtensionReference;
+import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IResourceChangeEvent;
 import org.eclipse.core.resources.IResourceChangeListener;
+import org.eclipse.core.resources.IResourceDelta;
 import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
@@ -22,7 +24,9 @@ import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IPluginRegistry;
+import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 
@@ -52,11 +56,39 @@ public class CDescriptorManager implements IResourceChangeListener {
 			return;
 		}
 		IResource resource = event.getResource();
-		if ( event.getType() == IResourceChangeEvent.PRE_DELETE ) {
-			if(resource.getType() == IResource.PROJECT ) {
-				fDescriptorMap.remove(resource);
-			}
-		}
+		
+		Object source = event.getSource();
+				
+		int eventType = event.getType();
+		
+		switch(eventType) {
+			case IResourceChangeEvent.PRE_DELETE:
+				if (resource.getType() == IResource.PROJECT){
+					fDescriptorMap.remove(resource);
+				}			
+			break;
+			case IResourceChangeEvent.POST_CHANGE:
+				IResourceDelta delta= event.getDelta();				
+				if (delta == null) {
+					break;
+				}
+				IResource dResource = delta.getResource();
+				//if (0 != (delta.getFlags() & IResourceDelta.OPEN)) {
+					if (dResource instanceof IFile) {
+						IFile file = (IFile)dResource;
+
+						// the .cdtproject file has been deleted
+						if ((file != null) && (file.getName().endsWith(CDescriptor.DESCRIPTION_FILE_NAME)) && !file.exists()){
+							// must remove the corresponding reference to it in the fDescriptorMap
+							if (fDescriptorMap != null){
+								fDescriptorMap.remove(resource);
+							}
+						}
+						
+					}
+				//}
+			break;		
+		}				
 	}
 	
 
@@ -123,4 +155,27 @@ public class CDescriptorManager implements IResourceChangeListener {
 		}		
 		return (ICExtension[]) extensionList.toArray(new ICExtension[extensionList.size()]);
 	}	
+
+    /**
+     * Must remove an existing .cdtproject file before we generate a new one when converting
+     */
+    public static void removeExistingCdtProjectFile(IProject project){
+    	IFile file = project.getFile(CDescriptor.DESCRIPTION_FILE_NAME);
+    	IProgressMonitor monitor = new  NullProgressMonitor();
+    		
+		// update the resource content
+		if ((file != null) && file.exists()) {
+			try{
+				file.delete(true, monitor);
+				// remove reference from the fDescriptorMap
+				if (fDescriptorMap != null){
+					fDescriptorMap.remove(project);
+				}	
+
+				project.refreshLocal(1, monitor);		
+			}catch(CoreException ce){
+				CCorePlugin.log(ce);
+			}
+		}    	
+    }
 }
diff --git a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/COwner.java b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/COwner.java
index c9a14481246..1d61f2b8651 100644
--- a/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/COwner.java
+++ b/core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/core/COwner.java
@@ -24,9 +24,9 @@ public class COwner implements ICOwnerInfo {
 	public COwner(String id) throws CoreException {
 		ownerID = id;
 		IExtensionPoint extpoint = CCorePlugin.getDefault().getDescriptor().getExtensionPoint("CProject");
-		if (extpoint != null) {
-			extension =  extpoint.getExtension(ownerID);
-		} else {
+		extension =  extpoint.getExtension(ownerID);
+		
+		if (extension == null) {
 			IStatus status = new Status(IStatus.ERROR, CCorePlugin.PLUGIN_ID, -1, "Invalid CDTProject owner ID", (Throwable)null);
 			throw new CoreException(status);
 		}