diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCPPBindingResolutionTest.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCPPBindingResolutionTest.java
index 6c5d5c89bcc..04e62edd2ce 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCPPBindingResolutionTest.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCPPBindingResolutionTest.java
@@ -1258,6 +1258,21 @@ public abstract class IndexCPPBindingResolutionTest extends IndexBindingResoluti
 		getBindingFromASTName("a= 1", 1);
 		getBindingFromASTName("b= 1", 1);
 	}
+	
+	// namespace x {
+	//    int a(int);
+	// }
+    // using namespace x;
+	// using x::a;
+	
+	// #include "header.h"
+	// void test() {
+	//    a(1);
+	// }
+    public void testLegalConflictWithUsingDeclaration() throws Exception {
+		getBindingFromASTName("a(1)", 1);
+    } 
+
 
 	/* CPP assertion helpers */
 	/* ##################################################################### */
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPScopeMapper.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPScopeMapper.java
index 1a7f5ea049d..e73099db925 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPScopeMapper.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPScopeMapper.java
@@ -21,8 +21,10 @@ import org.eclipse.cdt.core.dom.ast.DOMException;
 import org.eclipse.cdt.core.dom.ast.IASTName;
 import org.eclipse.cdt.core.dom.ast.IBinding;
 import org.eclipse.cdt.core.dom.ast.IScope;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPNamespace;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPNamespaceScope;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPUsingDirective;
+import org.eclipse.cdt.core.index.IIndexBinding;
 import org.eclipse.cdt.core.index.IIndexFileSet;
 import org.eclipse.cdt.internal.core.index.IIndexScope;
 
@@ -62,7 +64,7 @@ public class CPPScopeMapper {
 			if (parent instanceof IIndexScope) {
 				return mapToASTScope((IIndexScope) parent);
 			}
-			return fTuScope;
+			return fTu.getScope();
 		}
 
 		public IName getScopeName() throws DOMException {
@@ -99,7 +101,7 @@ public class CPPScopeMapper {
 		public IScope getContainingScope() {
 			final IScope scope= fDirective.getContainingScope();
 			if (scope == null) {
-				return fTuScope;
+				return fTu.getScope();
 			}
 			return scope;
 		}
@@ -118,11 +120,11 @@ public class CPPScopeMapper {
 	private final HashMap<IIndexScope, IScope> fMappedScopes= new HashMap<IIndexScope, IScope>();
 	private final HashMap<String, NamespaceScopeWrapper> fNamespaceWrappers= new HashMap<String, NamespaceScopeWrapper>();
 	private final Map<String, List<UsingDirectiveWrapper>> fPerName= new HashMap<String, List<UsingDirectiveWrapper>>();
-	private final CPPNamespaceScope fTuScope;
+	private final CPPASTTranslationUnit fTu;
 
 
 	public CPPScopeMapper(CPPASTTranslationUnit tu) {
-		fTuScope= tu.getScope();
+		fTu= tu;
 	}
 
 	/**
@@ -169,13 +171,14 @@ public class CPPScopeMapper {
 	}
 
 	private String getReverseQualifiedName(IScope scope) throws DOMException {
-		if (scope == fTuScope || scope == null) {
+		final CPPNamespaceScope tuscope = fTu.getScope();
+		if (scope == tuscope || scope == null) {
 			return "";    //$NON-NLS-1$
 		}
 		StringBuilder buf= new StringBuilder();
 		buf.append(scope.getScopeName().toCharArray());
 		scope= scope.getParent();
-		while (scope != null && scope != fTuScope) {
+		while (scope != null && scope != tuscope) {
 			buf.append(':');  
 			buf.append(scope.getScopeName().toCharArray());
 			scope= scope.getParent();
@@ -188,14 +191,14 @@ public class CPPScopeMapper {
 	 */
 	public IScope mapToASTScope(IIndexScope scope) {
 		if (scope == null) {
-			return fTuScope;
+			return fTu.getScope();
 		}
 		if (scope instanceof ICPPNamespaceScope) {
 			IScope result= fMappedScopes.get(scope);
 			if (result == null) {
-				result= fTuScope.findNamespaceScope(scope);
+				result= fTu.getScope().findNamespaceScope(scope);
 				if (result == null) {
-					result= wrapNamespaceScope(scope);
+					result= wrapNamespaceScope((ICPPNamespaceScope) scope);
 				}
 				fMappedScopes.put(scope, result);
 			}
@@ -204,12 +207,12 @@ public class CPPScopeMapper {
 		return scope;
 	}
 
-	private IScope wrapNamespaceScope(IIndexScope scope) {
+	private IScope wrapNamespaceScope(ICPPNamespaceScope scope) {
 		try {
 			String rqname= getReverseQualifiedName(scope);
 			NamespaceScopeWrapper result= fNamespaceWrappers.get(rqname);
 			if (result == null) {
-				result= new NamespaceScopeWrapper((ICPPNamespaceScope) scope);
+				result= new NamespaceScopeWrapper(getCompositeNamespaceScope(scope));
 				fNamespaceWrappers.put(rqname, result);
 			}
 			return result;
@@ -218,4 +221,14 @@ public class CPPScopeMapper {
 			return null;
 		}	
 	}
+	
+	private ICPPNamespaceScope getCompositeNamespaceScope(ICPPNamespaceScope scope) throws DOMException {
+		if (scope instanceof IIndexScope) {
+			IIndexBinding binding= fTu.getIndex().adaptBinding(((IIndexScope) scope).getScopeBinding());
+			if (binding instanceof ICPPNamespace) {
+				scope= ((ICPPNamespace) binding).getNamespaceScope();
+			}
+		}
+		return scope;
+	}
 }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPSemantics.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPSemantics.java
index 70886dfe887..bda2979901a 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPSemantics.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPSemantics.java
@@ -1074,7 +1074,7 @@ public class CPPSemantics {
 						IBinding binding = scope.getBinding( data.astName, false, fileSet );
 						if (binding instanceof CPPImplicitFunction || binding instanceof CPPImplicitTypedef) 
 							mergeResults( data, binding, true );
-						else
+						else if (binding != null)
 							b = new IBinding[] { binding };
 					} else {
 						b = scope.getBindings( data.astName, false, data.prefixLookup, fileSet );
@@ -2399,9 +2399,9 @@ public class CPPSemantics {
 		outer: for( int fnIdx = 0; fnIdx < numFns; fnIdx++ ){
 			currFn = (IFunction) fns[fnIdx];
 			
-			if( currFn == null || bestFn == currFn ||
-			    ( bestFn instanceof ICPPDelegate && ((ICPPDelegate)bestFn).getBinding() == currFn ) ||
-			    ( currFn instanceof ICPPDelegate && ((ICPPDelegate)currFn).getBinding() == bestFn ) )
+			if (currFn == null || bestFn == currFn ||
+					(bestFn instanceof ICPPDelegate && currFn.equals(((ICPPDelegate)bestFn).getBinding())) ||
+					(bestFn != null && currFn instanceof ICPPDelegate && bestFn.equals(((ICPPDelegate)currFn).getBinding())) )
 			{
 				continue;
 			}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/cpp/CompositeCPPNamespaceScope.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/cpp/CompositeCPPNamespaceScope.java
index ecb9fcab41c..cb415e16ebf 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/cpp/CompositeCPPNamespaceScope.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/index/composite/cpp/CompositeCPPNamespaceScope.java
@@ -20,7 +20,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPUsingDirective;
 import org.eclipse.cdt.core.index.IIndexBinding;
 import org.eclipse.cdt.core.index.IIndexFileSet;
 import org.eclipse.cdt.core.index.IIndexName;
-import org.eclipse.cdt.core.parser.util.ArrayUtil;
 import org.eclipse.cdt.internal.core.index.IIndexFragmentBinding;
 import org.eclipse.cdt.internal.core.index.IIndexScope;
 import org.eclipse.cdt.internal.core.index.composite.CompositeScope;
@@ -53,12 +52,13 @@ class CompositeCPPNamespaceScope extends CompositeScope implements ICPPNamespace
 	
 	public IBinding[] getBindings(IASTName name, boolean resolve, boolean prefixLookup, IIndexFileSet fileSet)
 			throws DOMException {
-		IBinding[] preresult = null;
+		IIndexFragmentBinding[][] preresult = new IIndexFragmentBinding[namespaces.length][];
 		for(int i=0; i<namespaces.length; i++) {
-			preresult = (IBinding[]) ArrayUtil.addAll(IBinding.class, preresult,
-					namespaces[i].getNamespaceScope().getBindings(name, resolve, prefixLookup, fileSet));
+			IBinding[] raw = namespaces[i].getNamespaceScope().getBindings(name, resolve, prefixLookup, fileSet);
+			preresult[i] = new IIndexFragmentBinding[raw.length];
+			System.arraycopy(raw, 0, preresult[i], 0, raw.length);
 		}
-		return processUncertainBindings(preresult);
+		return cf.getCompositeBindings(preresult);
 	}
 	
 	final public IBinding[] find(String name) throws DOMException {