diff --git a/OpenSim/Region/CoreModules/World/Terrain/FileLoaders/RAW32.cs b/OpenSim/Region/CoreModules/World/Terrain/FileLoaders/RAW32.cs
index 9fb7ef796e..d467abb80a 100644
--- a/OpenSim/Region/CoreModules/World/Terrain/FileLoaders/RAW32.cs
+++ b/OpenSim/Region/CoreModules/World/Terrain/FileLoaders/RAW32.cs
@@ -25,7 +25,10 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using System;
 using System.IO;
+
+using OpenSim.Framework;
 using OpenSim.Region.Framework.Interfaces;
 using OpenSim.Region.Framework.Scenes;
 
@@ -116,7 +119,15 @@ namespace OpenSim.Region.CoreModules.World.Terrain.FileLoaders
 
         public ITerrainChannel LoadStream(Stream s)
         {
-            TerrainChannel retval = new TerrainChannel();
+            // The raw format doesn't contain any dimension information.
+            // Guess the square dimensions by using the length of the raw file.
+            double dimension = Math.Sqrt((double)(s.Length / 4));
+            // Regions are always multiples of 256.
+            int trimmedDimension = (int)dimension - ((int)dimension % (int)Constants.RegionSize);
+            if (trimmedDimension < Constants.RegionSize)
+                trimmedDimension = (int)Constants.RegionSize;
+
+            TerrainChannel retval = new TerrainChannel(trimmedDimension, trimmedDimension);
 
             BinaryReader bs = new BinaryReader(s);
             int y;
diff --git a/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainTest.cs b/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainTest.cs
index 96c16a9a8e..29e80efcd0 100644
--- a/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainTest.cs
+++ b/OpenSim/Region/CoreModules/World/Terrain/Tests/TerrainTest.cs
@@ -80,7 +80,7 @@ namespace OpenSim.Region.CoreModules.World.Terrain.Tests
             effect = new LowerSphere();
 
             effect.PaintEffect(map, allowMask, midRegion, midRegion, -1.0, 2, 6.0);
-            Assert.That(map[127, midRegion] >= 0.0, "Lower should not lowering value below 0.0 at this point (127,128).");
+            Assert.That(map[127, midRegion] >= 0.0, "Lower should not lowering value below 0.0 at this point (127,128).");
             Assert.That(map[127, midRegion] == 0.0, "Lower brush should lowering value to 0.0 at this point (127,128).");
             Assert.That(map[125, midRegion] < 1.0, "Lower brush should lowering value at this point (124,128).");
             Assert.That(map[120, midRegion] == 1.0, "Lower brush should not change value at this point (120,128).");
diff --git a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
index 24709dcf74..60dc6c9676 100644
--- a/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
+++ b/OpenSim/Region/Framework/Scenes/TerrainChannel.cs
@@ -217,6 +217,10 @@ namespace OpenSim.Region.Framework.Scenes
         // ITerrainChannel.Merge
         public void Merge(ITerrainChannel newTerrain, Vector3 displacement, float radianRotation, Vector2 rotationDisplacement)
         {
+            m_log.DebugFormat("{0} Merge. inSize=<{1},{2}>, disp={3}, rot={4}, rotDisp={5}, outSize=<{6},{7}>", LogHeader,
+                                        newTerrain.Width, newTerrain.Height,
+                                        displacement, radianRotation, rotationDisplacement,
+                                        m_terrainData.SizeX, m_terrainData.SizeY);
             for (int xx = 0; xx < newTerrain.Width; xx++)
             {
                 for (int yy = 0; yy < newTerrain.Height; yy++)