Thank you kindly krtaylor for a patch to solve:

Linked objects won't scale together properly, only the root object scales. 
This happens with scaling both up and down or inputting numbers in the edit dialog.

1 files changed, 11 insertions, 0 deletions

diff --git a/OpenSim/Region/Environment/Scenes/InnerScene.cs b/OpenSim/Region/Environment/Scenes/InnerScene.cs
index ea4283f..8894db0 100644
--- a/OpenSim/Region/Environment/Scenes/InnerScene.cs
+++ b/OpenSim/Region/Environment/Scenes/InnerScene.cs
@@ -890,6 +890,17 @@ namespace OpenSim.Region.Environment.Scenes
                 }
             }
         }
+        public void UpdatePrimGroupScale(uint localID, LLVector3 scale, IClientAPI remoteClient)
+        {
+            SceneObjectGroup group = GetGroupByPrim(localID);
+            if (group != null)
+            {
+                if (PermissionsMngr.CanEditObjectPosition(remoteClient.AgentId, group.UUID))
+                {
+                    group.GroupResize(scale, localID);
+                }
+            }
+        }
 
         /// <summary>
         /// This handles the nifty little tool tip that you get when you drag your mouse over an object