Mantis#2354. Thank you kindly, Tglion for a patch that:

The average-value of modify.ModifyBlock.Height in LLClientView.cs:4170 
seem to be incorrect or it isn't the average? Mhhh...
So the terrain build -> Flaten Sphere is unuseable.
I have put in a patch that contains a workaround while 
the main problem is not solved.

1 files changed, 1 insertions, 0 deletions

diff --git a/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs b/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
index d2f46e5..b2138aa 100644
--- a/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
+++ b/OpenSim/Region/ClientStack/LindenUDP/LLClientView.cs
@@ -4179,6 +4179,7 @@ namespace OpenSim.Region.ClientStack.LindenUDP
                                     handlerModifyTerrain = OnModifyTerrain;
                                     if (handlerModifyTerrain != null)
                                     {
+                                        modify.ModifyBlock.Height = -1; // Hack, i don't know why the value is wrong
                                         handlerModifyTerrain(modify.ModifyBlock.Height, modify.ModifyBlock.Seconds,
                                                              modify.ModifyBlock.BrushSize,
                                                              modify.ModifyBlock.Action, modify.ParcelData[i].North,