diff --git a/mozilla/extensions/transformiix/build/XSLTProcessorModule.cpp b/mozilla/extensions/transformiix/build/XSLTProcessorModule.cpp
index dafc989ac96..38a9bdcce80 100755
--- a/mozilla/extensions/transformiix/build/XSLTProcessorModule.cpp
+++ b/mozilla/extensions/transformiix/build/XSLTProcessorModule.cpp
@@ -146,10 +146,14 @@ RegisterTransformiix(nsIComponentManager *aCompMgr,
                                   PR_TRUE, PR_TRUE, getter_Copies(previous));
     NS_ENSURE_SUCCESS(rv, rv);
 
+    char* iidString = NS_GET_IID(nsIDocumentTransformer).ToString();
+    if (!iidString)
+      return NS_ERROR_OUT_OF_MEMORY;
     rv = catman->AddCategoryEntry(JAVASCRIPT_DOM_INTERFACE,
                                   "nsIDocumentTransformer",
-                                  NS_GET_IID(nsIDocumentTransformer).ToString(),
+                                  iidString,
                                   PR_TRUE, PR_TRUE, getter_Copies(previous));
+    nsCRT::free(iidString);
 
     return rv;
 }
diff --git a/mozilla/extensions/xmlextras/build/src/nsXMLExtrasModule.cpp b/mozilla/extensions/xmlextras/build/src/nsXMLExtrasModule.cpp
index c2c84b02703..3e71a793dd6 100644
--- a/mozilla/extensions/xmlextras/build/src/nsXMLExtrasModule.cpp
+++ b/mozilla/extensions/xmlextras/build/src/nsXMLExtrasModule.cpp
@@ -282,16 +282,26 @@ RegisterXMLExtras(nsIComponentManager *aCompMgr,
                                 PR_TRUE, PR_TRUE, getter_Copies(previous));
   NS_ENSURE_SUCCESS(rv, rv);
 
+  char* iidString = NS_GET_IID(nsIXMLHttpRequest).ToString();
+  if (!iidString)
+    return NS_ERROR_OUT_OF_MEMORY;
+
   rv = catman->AddCategoryEntry(JAVASCRIPT_DOM_INTERFACE,
                                 "nsIXMLHttpRequest",
-                                NS_GET_IID(nsIXMLHttpRequest).ToString(),
+                                iidString,
                                 PR_TRUE, PR_TRUE, getter_Copies(previous));
+  nsCRT::free(iidString);
   NS_ENSURE_SUCCESS(rv, rv);
 
+  iidString = NS_GET_IID(nsIJSXMLHttpRequest).ToString();
+  if (!iidString)
+    return NS_ERROR_OUT_OF_MEMORY;
+
   rv = catman->AddCategoryEntry(JAVASCRIPT_DOM_INTERFACE,
                                 "nsIJSXMLHttpRequest",
-                                NS_GET_IID(nsIJSXMLHttpRequest).ToString(),
+                                iidString,
                                 PR_TRUE, PR_TRUE, getter_Copies(previous));
+  nsCRT::free(iidString);
   NS_ENSURE_SUCCESS(rv, rv);
 
   rv = catman->AddCategoryEntry(JAVASCRIPT_GLOBAL_CONSTRUCTOR_CATEGORY,