diff --git a/SCsub b/SCsub
index a929575..bf55ecc 100644
--- a/SCsub
+++ b/SCsub
@@ -15,7 +15,8 @@ sources = [
 ]
 
 module_env = env.Clone()
-module_env.Append(CXXFLAGS=['-O2', '-std=c++11', '-Wno-sign-compare', '-Wno-strict-aliasing'])
+#module_env.Append(CXXFLAGS=['-O2', '-std=c++11', '-Wno-sign-compare', '-Wno-strict-aliasing'])
+module_env.Append(CXXFLAGS=['-std=c++11', '-Wno-sign-compare', '-Wno-strict-aliasing'])
 
 if ARGUMENTS.get('lportal_shared', 'no') == 'yes':
     # Shared lib compilation
diff --git a/ldebug.h b/ldebug.h
index 23b733d..10b4339 100644
--- a/ldebug.h
+++ b/ldebug.h
@@ -24,6 +24,7 @@
 // you won't be able to get frame debugging of the visibility tree though.
 #ifdef DEBUG_ENABLED
 
+#pragma message ("LPortal DEBUG_ENABLED")
 #define LPRINT_RUN(a, b) {String sz;\
 for (int n=0; n<Lawn::LDebug::m_iTabDepth; n++)\
 sz += "\t";\
diff --git a/lportal.cpp b/lportal.cpp
index a276bf4..32416ed 100644
--- a/lportal.cpp
+++ b/lportal.cpp
@@ -234,15 +234,32 @@ void LPortal::CreateGeometry(PoolVector<Vector3> p_vertices, const Transform &tr
 	int nPoints = p_vertices.size();
 	ERR_FAIL_COND(nPoints < 3);
 
-	m_ptsWorld.resize(nPoints);
+	m_ptsWorld.clear();
 
 	//print("\t\t\tLPortal::CreateGeometry nPoints : " + itos(nPoints));
 
 	for (int n=0; n<nPoints; n++)
 	{
 		Vector3 ptWorld = trans.xform(p_vertices[n]);
-		m_ptsWorld.set(n, ptWorld);
-		m_ptCentre += ptWorld;
+
+		// new!! test for duplicates. Some geometry may contain duplicate verts in portals which will muck up
+		// the winding etc...
+		bool bDuplicate = false;
+		for (int m=0; m<m_ptsWorld.size(); m++)
+		{
+			Vector3 ptDiff = ptWorld - m_ptsWorld[m];
+			if (ptDiff.length() < 0.001f)
+			{
+				bDuplicate = true;
+				break;
+			}
+		}
+
+		if (!bDuplicate)
+		{
+			m_ptsWorld.push_back(ptWorld);
+			m_ptCentre += ptWorld;
+		}
 
 		//print("\t\t\t\t" + itos(n) + "\tLocal : " + Variant(p_vertices[n]) + "\tWorld : " + ptWorld);
 	}