diff --git a/OpenMetaverse.StructuredData/StructuredData.cs b/OpenMetaverse.StructuredData/StructuredData.cs
index 5e370ae3..99d84c83 100644
--- a/OpenMetaverse.StructuredData/StructuredData.cs
+++ b/OpenMetaverse.StructuredData/StructuredData.cs
@@ -85,7 +85,7 @@ namespace OpenMetaverse.StructuredData
         public virtual string AsString() { return String.Empty; }
         public virtual UUID AsUUID() { return UUID.Zero; }
         public virtual DateTime AsDate() { return Utils.Epoch; }
-        public virtual Uri AsUri() { return new Uri(String.Empty); }
+        public virtual Uri AsUri() { return new Uri("http://null/"); }
         public virtual byte[] AsBinary() { return Utils.EmptyBytes; }
         public virtual Vector2 AsVector2() { return Vector2.Zero; }
         public virtual Vector3 AsVector3() { return Vector3.Zero; }
diff --git a/OpenMetaverse/Types/CircularQueue.cs b/OpenMetaverse/Types/CircularQueue.cs
index fb6bcc01..3c2ac42b 100644
--- a/OpenMetaverse/Types/CircularQueue.cs
+++ b/OpenMetaverse/Types/CircularQueue.cs
@@ -53,15 +53,18 @@ namespace OpenMetaverse
         /// <param name="queue">Circular queue to copy</param>
         public CircularQueue(CircularQueue<T> queue)
         {
-            capacity = queue.capacity;
-            Items = new T[capacity];
-            syncRoot = new object();
+            lock (queue.syncRoot)
+            {
+                capacity = queue.capacity;
+                Items = new T[capacity];
+                syncRoot = new object();
 
-            for (int i = 0; i < capacity; i++)
-                Items[i] = queue.Items[i];
+                for (int i = 0; i < capacity; i++)
+                    Items[i] = queue.Items[i];
 
-            first = queue.first;
-            next = queue.next;
+                first = queue.first;
+                next = queue.next;
+            }
         }
 
         public void Clear()