Index: OpenMetaverse/Primitives/Primitive.cs
===================================================================
--- OpenMetaverse/Primitives/Primitive.cs       (revision 177)
+++ OpenMetaverse/Primitives/Primitive.cs       (working copy)
@@ -1548,7 +1548,7 @@
                 PrimData.Material.GetHashCode() ^
                 MediaURL.GetHashCode() ^
                 //TODO: NameValues?
-                Properties.OwnerID.GetHashCode() ^
+                (Properties != null ? Properties.OwnerID.GetHashCode() : 0) ^
                 ParentID.GetHashCode() ^
                 PrimData.PathBegin.GetHashCode() ^
                 PrimData.PathCurve.GetHashCode() ^