diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CSourceViewer.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CSourceViewer.java
index fe9279e41b5..6a62d85857b 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CSourceViewer.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CSourceViewer.java
@@ -41,6 +41,8 @@ import org.eclipse.swt.widgets.Display;
 import org.eclipse.ui.texteditor.AbstractDecoratedTextEditorPreferenceConstants;
 import org.eclipse.ui.texteditor.AbstractTextEditor;
 
+import org.eclipse.cdt.ui.PreferenceConstants;
+
 import org.eclipse.cdt.internal.ui.text.CSourceViewerConfiguration;
 
 /**
@@ -157,6 +159,8 @@ public class CSourceViewer extends ProjectionViewer implements IPropertyChangeLi
 		if (fPreferenceStore != null) {
 			fPreferenceStore.addPropertyChangeListener(this);
 			initializeViewerColors();
+			// init flag here in case we start in segmented mode
+			fWasProjectionMode= fPreferenceStore.getBoolean(PreferenceConstants.EDITOR_FOLDING_ENABLED);
 		}
 
 		fIsConfigured= true;
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/folding/DefaultCFoldingStructureProvider.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/folding/DefaultCFoldingStructureProvider.java
index cb1a55880e4..becd6734fde 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/folding/DefaultCFoldingStructureProvider.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/folding/DefaultCFoldingStructureProvider.java
@@ -125,8 +125,10 @@ public class DefaultCFoldingStructureProvider implements ICFoldingStructureProvi
 			try {
 				FoldingStructureComputationContext ctx= createContext(fInitialReconcilePending);
 				fInitialReconcilePending= false;
-				ctx.fAST= ast;
-	            update(ctx);
+				if (ctx != null) {
+					ctx.fAST= ast;
+					update(ctx);
+				}
 			} finally {
 				fReconciling= false;
 			}
@@ -380,7 +382,6 @@ public class DefaultCFoldingStructureProvider implements ICFoldingStructureProvi
 
 			IRegion preRegion;
 			if (firstLine < captionLine) {
-//				preRegion= new Region(offset + prefixEnd, contentStart - prefixEnd);
 				int preOffset= document.getLineOffset(firstLine);
 				IRegion preEndLineInfo= document.getLineInformation(captionLine);
 				int preEnd= preEndLineInfo.getOffset();
@@ -422,33 +423,6 @@ public class DefaultCFoldingStructureProvider implements ICFoldingStructureProvi
 			return 0;
 		}
 
-//		/**
-//		 * Finds the offset of the first identifier part within <code>content</code>.
-//		 * Returns 0 if none is found.
-//		 *
-//		 * @param content the content to search
-//		 * @return the first index of a unicode identifier part, or zero if none can
-//		 *         be found
-//		 */
-//		private int findPrefixEnd(final CharSequence content) {
-//			// return the index after the leading '/*' or '/**'
-//			int len= content.length();
-//			int i= 0;
-//			while (i < len && isWhiteSpace(content.charAt(i)))
-//				i++;
-//			if (len >= i + 2 && content.charAt(i) == '/' && content.charAt(i + 1) == '*')
-//				if (len >= i + 3 && content.charAt(i + 2) == '*')
-//					return i + 3;
-//				else
-//					return i + 2;
-//			else
-//				return i;
-//		}
-//
-//		private boolean isWhiteSpace(char c) {
-//			return c == ' ' || c == '\t';
-//		}
-
 		/*
 		 * @see org.eclipse.jface.text.source.projection.IProjectionPosition#computeCaptionOffset(org.eclipse.jface.text.IDocument)
 		 */