diff --git a/include/graphics/GraphicsDrawer.h b/include/graphics/GraphicsDrawer.h
index f3b060a8..97dfd19b 100644
--- a/include/graphics/GraphicsDrawer.h
+++ b/include/graphics/GraphicsDrawer.h
@@ -54,7 +54,7 @@ namespace hpl {
 	class cGfxBufferCompare
 	{
 	public:
-		bool operator()(const cGfxBufferObject& aObjectA,const cGfxBufferObject& aObjectB);
+		bool operator()(const cGfxBufferObject& aObjectA,const cGfxBufferObject& aObjectB) const;
 	};
 
 	typedef std::multiset<cGfxBufferObject,cGfxBufferCompare> tGfxBufferSet;
diff --git a/include/graphics/Renderer2D.h b/include/graphics/Renderer2D.h
index 6fe7ed9c..074b1523 100644
--- a/include/graphics/Renderer2D.h
+++ b/include/graphics/Renderer2D.h
@@ -48,14 +48,14 @@ namespace hpl {
 	class cRenderObject2DCompare
 	{
 	public:
-		bool operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB);
+		bool operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB) const;
 	};
 
 	//For transparent objects
 	class cRenderTransObjectCompare
 	{
 	public:
-		bool operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB);
+		bool operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB) const;
 	};
 
 	typedef std::multiset<cRenderObject2D,cRenderObject2DCompare> tRenderObjectSet;
diff --git a/include/gui/GuiSet.h b/include/gui/GuiSet.h
index d310ccaa..a7e09fe6 100644
--- a/include/gui/GuiSet.h
+++ b/include/gui/GuiSet.h
@@ -73,7 +73,7 @@ namespace hpl {
 	class cGuiRenderObjectCompare
 	{
 	public:
-		bool operator()(const cGuiRenderObject& aObjectA, const cGuiRenderObject& aObjectB);
+		bool operator()(const cGuiRenderObject& aObjectA, const cGuiRenderObject& aObjectB) const;
 	};
 
 	typedef std::multiset<cGuiRenderObject,cGuiRenderObjectCompare> tGuiRenderObjectSet;
diff --git a/sources/graphics/GraphicsDrawer.cpp b/sources/graphics/GraphicsDrawer.cpp
index acf28274..ebf85ebf 100644
--- a/sources/graphics/GraphicsDrawer.cpp
+++ b/sources/graphics/GraphicsDrawer.cpp
@@ -74,7 +74,7 @@ namespace hpl {
 
 	//-----------------------------------------------------------------------
 
-	bool cGfxBufferCompare::operator()(const cGfxBufferObject& aObjectA,const cGfxBufferObject& aObjectB)
+	bool cGfxBufferCompare::operator()(const cGfxBufferObject& aObjectA,const cGfxBufferObject& aObjectB) const
 	{
 		if(aObjectA.GetZ() != aObjectB.GetZ())
 		{
diff --git a/sources/graphics/Renderer2D.cpp b/sources/graphics/Renderer2D.cpp
index 8cfeb355..eae5a67e 100644
--- a/sources/graphics/Renderer2D.cpp
+++ b/sources/graphics/Renderer2D.cpp
@@ -87,7 +87,7 @@ namespace hpl {
 
 	//-----------------------------------------------------------------------
 	////////////////////// RENDER OBJECT COMPARE ////////////////////////////
-	bool cRenderObject2DCompare::operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB)
+	bool cRenderObject2DCompare::operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB) const
 	{
 		if(aObjectA.GetMaterial()->GetTexture(eMaterialTexture_Diffuse) !=
 			aObjectB.GetMaterial()->GetTexture(eMaterialTexture_Diffuse))
@@ -115,7 +115,7 @@ namespace hpl {
 
 	////////////////////// TRANS RENDER OBJECT COMPARE ////////////////////////////
 
-	bool cRenderTransObjectCompare::operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB)
+	bool cRenderTransObjectCompare::operator()(const cRenderObject2D &aObjectA,const cRenderObject2D &aObjectB) const
 	{
 		if(aObjectA.GetZ() != aObjectB.GetZ())
 		{
@@ -895,13 +895,17 @@ namespace hpl {
 			//MAYBE TODO: Fix so that the shadows from different edges share vertices
 
 			// Add vertexes and indexes to the vertex batcher
-			mpLowLevelGraphics->AddVertexToBatch(&cVertex(vPointPos[0],ShadowColor));
-			mpLowLevelGraphics->AddVertexToBatch(&cVertex(vPointPos[1],ShadowColor));
+			cVertex v1 = cVertex(vPointPos[0],ShadowColor);
+			mpLowLevelGraphics->AddVertexToBatch(&v1);
+			cVertex v2 = cVertex(vPointPos[1],ShadowColor);
+			mpLowLevelGraphics->AddVertexToBatch(&v2);
 			mpLowLevelGraphics->AddIndexToBatch(lFirstIndex);
 			mpLowLevelGraphics->AddIndexToBatch(lFirstIndex+1);
 
-			mpLowLevelGraphics->AddVertexToBatch(&cVertex(vEndPos[0],ShadowColor));
-			mpLowLevelGraphics->AddVertexToBatch(&cVertex(vEndPos[1],ShadowColor));
+			cVertex v3 = cVertex(vEndPos[0],ShadowColor);
+			mpLowLevelGraphics->AddVertexToBatch(&v3);
+			cVertex v4 = cVertex(vEndPos[1],ShadowColor);
+			mpLowLevelGraphics->AddVertexToBatch(&v4);
 			mpLowLevelGraphics->AddIndexToBatch(lFirstIndex+2);
 
 			mpLowLevelGraphics->AddIndexToBatch(lFirstIndex+1);
@@ -920,7 +924,8 @@ namespace hpl {
 
 			//If we had an extra point one for triangle is needed.
 			if(bExtraPos){
-				mpLowLevelGraphics->AddVertexToBatch(&cVertex(vExtraPos,ShadowColor));
+				cVertex v5 = cVertex(vExtraPos,ShadowColor);
+				mpLowLevelGraphics->AddVertexToBatch(&v5);
 
 				mpLowLevelGraphics->AddIndexToBatch(lFirstIndex+3);
 				mpLowLevelGraphics->AddIndexToBatch(lFirstIndex+2);
diff --git a/sources/gui/GuiSet.cpp b/sources/gui/GuiSet.cpp
index d77e9df8..49cc970b 100644
--- a/sources/gui/GuiSet.cpp
+++ b/sources/gui/GuiSet.cpp
@@ -64,7 +64,7 @@ namespace hpl {
 	//-----------------------------------------------------------------------
 
 	bool cGuiRenderObjectCompare::operator()(	const cGuiRenderObject& aObjectA,
-												const cGuiRenderObject& aObjectB)
+												const cGuiRenderObject& aObjectB) const
 	{
 		//Z
 		float fZA = aObjectA.mvPos.z;
diff --git a/sources/impl/LowLevelSystemSDL.cpp b/sources/impl/LowLevelSystemSDL.cpp
index 7c28d567..81bad49c 100644
--- a/sources/impl/LowLevelSystemSDL.cpp
+++ b/sources/impl/LowLevelSystemSDL.cpp
@@ -27,6 +27,7 @@
 #endif
 
 #ifndef WIN32
+#include <unistd.h>
 // Include FLTK
 #include "FL/fl_ask.H"
 #endif
diff --git a/sources/impl/PhysicsBodyNewton.cpp b/sources/impl/PhysicsBodyNewton.cpp
index 3b4f6efc..757af4b6 100644
--- a/sources/impl/PhysicsBodyNewton.cpp
+++ b/sources/impl/PhysicsBodyNewton.cpp
@@ -101,7 +101,8 @@ namespace hpl {
 		if(cPhysicsBodyNewton::mbUseCallback==false) return;
 
 		cPhysicsBodyNewton *pRigidBody = static_cast<cPhysicsBodyNewton*>(apEntity);
-		NewtonBodySetMatrix(pRigidBody->mpNewtonBody, &apEntity->GetLocalMatrix().GetTranspose().m[0][0]);
+        hpl::cMatrix<float> transpose = apEntity->GetLocalMatrix().GetTranspose();
+		NewtonBodySetMatrix(pRigidBody->mpNewtonBody, &transpose.m[0][0]);
 
 		if(pRigidBody->mpNode) pRigidBody->mpNode->SetMatrix(apEntity->GetLocalMatrix());
 	}