diff --git a/rdf/base/src/nsContainerCursor.cpp b/rdf/base/src/nsContainerCursor.cpp
index a6664dc71f22..85631cb98207 100644
--- a/rdf/base/src/nsContainerCursor.cpp
+++ b/rdf/base/src/nsContainerCursor.cpp
@@ -184,6 +184,9 @@ ContainerCursorImpl::Advance(void)
     if (NS_FAILED(rv = mDataSource->GetTarget(mContainer, kRDF_nextVal, PR_TRUE, &nextNode)))
         goto done;
 
+    if (rv == NS_RDF_NO_VALUE)
+        goto done;
+
     if (NS_FAILED(rv = nextNode->QueryInterface(kIRDFLiteralIID, (void**) &nextVal)))
         goto done;
 
diff --git a/rdf/base/src/nsRDFXMLDataSource.cpp b/rdf/base/src/nsRDFXMLDataSource.cpp
index 9f176552a6c0..f7ef592dd6ee 100644
--- a/rdf/base/src/nsRDFXMLDataSource.cpp
+++ b/rdf/base/src/nsRDFXMLDataSource.cpp
@@ -1214,6 +1214,10 @@ RDFXMLDataSourceImpl::SerializeMember(nsIOutputStream* aStream,
         if (NS_FAILED(rv = cursor->GetTarget(&node)))
             break;
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null item in cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         // If it's a resource, then output a "<RDF:li resource=... />"
         // tag, because we'll be dumping the resource separately. (We
         // iterate thru all the resources in the datasource,
diff --git a/rdf/base/src/rdfutil.cpp b/rdf/base/src/rdfutil.cpp
index 2eea7ff5a749..6903926cd56d 100644
--- a/rdf/base/src/rdfutil.cpp
+++ b/rdf/base/src/rdfutil.cpp
@@ -728,6 +728,9 @@ rdf_ContainerGetNextValue(nsIRDFDataSource* ds,
     if (NS_FAILED(rv = ds->GetTarget(container, kRDF_nextVal, PR_TRUE, &nextValNode)))
         goto done;
 
+    if (rv == NS_RDF_NO_VALUE)
+        goto done;
+
     if (NS_FAILED(rv = nextValNode->QueryInterface(kIRDFLiteralIID, (void**) &nextValLiteral)))
         goto done;
 
@@ -841,6 +844,10 @@ rdf_ContainerRemoveElement(nsIRDFDataSource* aDataSource,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null item in cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         PRBool eq;
         if (NS_FAILED(rv = element->EqualsNode(aElement, &eq))) {
             NS_ERROR("severe error on equality check");
@@ -886,6 +893,10 @@ rdf_ContainerRemoveElement(nsIRDFDataSource* aDataSource,
                 return rv;
             }
 
+            NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null value in cursor");
+            if (rv == NS_RDF_NO_VALUE)
+                continue;
+
             if (NS_FAILED(rv = elements->GetLabel(getter_AddRefs(ordinal)))) {
                 NS_ERROR("unable to get element's ordinal index");
                 return rv;
@@ -1032,6 +1043,10 @@ rdf_ContainerInsertElementAt(nsIRDFDataSource* aDataSource,
                 return rv;
             }
 
+            NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null value in cursor");
+            if (rv == NS_RDF_NO_VALUE)
+                continue;
+
             if (NS_FAILED(rv = aDataSource->Unassert(aContainer, ordinal, element))) {
                 NS_ERROR("unable to remove element from container");
                 return rv;
@@ -1115,6 +1130,10 @@ rdf_ContainerIndexOf(nsIRDFDataSource* aDataSource,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null value in cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         // Okay, we've found it.
         nsCOMPtr<nsIRDFResource> ordinal;
         if (NS_FAILED(rv = elements->GetLabel(getter_AddRefs(ordinal)))) {
diff --git a/rdf/content/src/nsRDFMenuBuilder.cpp b/rdf/content/src/nsRDFMenuBuilder.cpp
index 39a8ffe4633b..b94411eceb64 100644
--- a/rdf/content/src/nsRDFMenuBuilder.cpp
+++ b/rdf/content/src/nsRDFMenuBuilder.cpp
@@ -277,6 +277,10 @@ RDFMenuBuilderImpl::AddWidgetItem(nsIContent* aElement,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "arc-out with no target: fix your arcs-out cursor!");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         nsCOMPtr<nsIRDFResource> resource;
         nsCOMPtr<nsIRDFLiteral> literal;
 
diff --git a/rdf/content/src/nsRDFToolbarBuilder.cpp b/rdf/content/src/nsRDFToolbarBuilder.cpp
index a8db17b7901b..8070a22fcc1e 100644
--- a/rdf/content/src/nsRDFToolbarBuilder.cpp
+++ b/rdf/content/src/nsRDFToolbarBuilder.cpp
@@ -259,6 +259,10 @@ RDFToolbarBuilderImpl::AddWidgetItem(nsIContent* aElement,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "arc-out with no target: fix your arcs out cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         nsCOMPtr<nsIRDFResource> resource;
         nsCOMPtr<nsIRDFLiteral> literal;
 
diff --git a/rdf/content/src/nsRDFTreeBuilder.cpp b/rdf/content/src/nsRDFTreeBuilder.cpp
index a8699e955ceb..dfafa9191262 100644
--- a/rdf/content/src/nsRDFTreeBuilder.cpp
+++ b/rdf/content/src/nsRDFTreeBuilder.cpp
@@ -593,6 +593,10 @@ RDFTreeBuilderImpl::AddWidgetItem(nsIContent* aElement,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "arc-out with no target: fix your arcs-out cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         nsCOMPtr<nsIRDFResource> resource;
         nsCOMPtr<nsIRDFLiteral> literal;
 
diff --git a/rdf/content/src/nsRDFXULBuilder.cpp b/rdf/content/src/nsRDFXULBuilder.cpp
index 5b1da8b9482c..23ea736f1860 100644
--- a/rdf/content/src/nsRDFXULBuilder.cpp
+++ b/rdf/content/src/nsRDFXULBuilder.cpp
@@ -573,6 +573,10 @@ RDFXULBuilderImpl::CreateContents(nsIContent* aElement)
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null value in cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         if (NS_FAILED(AppendChild(aElement, child))) {
             NS_ERROR("problem appending child to content model");
             return rv;
@@ -1446,6 +1450,11 @@ RDFXULBuilderImpl::CreateElement(nsIRDFResource* aResource,
         return rv;
     }
 
+    NS_ASSERTION(rv != NS_RDF_NO_VALUE, "no node type");
+    if (rv == NS_RDF_NO_VALUE)
+        return NS_ERROR_UNEXPECTED;
+        
+
     nsCOMPtr<nsIRDFResource> type;
     if (NS_FAILED(rv = typeNode->QueryInterface(kIRDFResourceIID, getter_AddRefs(type)))) {
         NS_ERROR("type wasn't a resource");
@@ -1573,6 +1582,10 @@ RDFXULBuilderImpl::CreateHTMLElement(nsIRDFResource* aResource,
             return rv;
         }
 
+        NS_ASSERTION(rv != NS_RDF_NO_VALUE, "null value in cursor");
+        if (rv == NS_RDF_NO_VALUE)
+            continue;
+
         // Add the attribute to the newly constructed element
         if (NS_FAILED(rv = AddAttribute(element, property, value))) {
             NS_ERROR("unable to add attribute to element");