diff --git a/FDTD/extensions/engine_ext_mur_abc.cpp b/FDTD/extensions/engine_ext_mur_abc.cpp
index 3fee2dd..d877497 100644
--- a/FDTD/extensions/engine_ext_mur_abc.cpp
+++ b/FDTD/extensions/engine_ext_mur_abc.cpp
@@ -112,8 +112,9 @@ void Engine_Ext_Mur_ABC::DoPreVoltageUpdates(int threadID)
 	case Engine::SSE:
 		{
 			Engine_sse* eng_sse = (Engine_sse*) m_Eng;
-			for (pos[m_nyP]=0; pos[m_nyP]<m_numLines[0]; ++pos[m_nyP])
+			for (unsigned int lineX=0; lineX<m_numX.at(threadID); ++lineX)
 			{
+				pos[m_nyP]=lineX+m_start.at(threadID);
 				pos_shift[m_nyP] = pos[m_nyP];
 				for (pos[m_nyPP]=0; pos[m_nyPP]<m_numLines[1]; ++pos[m_nyPP])
 				{
diff --git a/FDTD/extensions/engine_extension.h b/FDTD/extensions/engine_extension.h
index 91d5cb1..2c53c21 100644
--- a/FDTD/extensions/engine_extension.h
+++ b/FDTD/extensions/engine_extension.h
@@ -21,10 +21,10 @@
 #define ENG_EXT_PRIO_DEFAULT 0 //default engine extension priority
 
 // priority definitions for some important extensions
-#define ENG_EXT_PRIO_UPML				1e6; //unaxial pml extension priority
-#define ENG_EXT_PRIO_EXCITATION			3000 //excitation priority
-#define ENG_EXT_PRIO_CYLINDER			2000 //cylindrial extension priority
-#define ENG_EXT_PRIO_CYLINDERMULTIGRID	-1000; //cylindrial multi-grid extension priority
+#define ENG_EXT_PRIO_UPML				+1e6  //unaxial pml extension priority
+#define ENG_EXT_PRIO_EXCITATION			-1000 //excitation priority
+#define ENG_EXT_PRIO_CYLINDER			-2000 //cylindrial extension priority
+#define ENG_EXT_PRIO_CYLINDERMULTIGRID	-3000 //cylindrial multi-grid extension priority
 
 #include <string>
 
diff --git a/FDTD/extensions/operator_ext_mur_abc.cpp b/FDTD/extensions/operator_ext_mur_abc.cpp
index 26a209c..71d7ad9 100644
--- a/FDTD/extensions/operator_ext_mur_abc.cpp
+++ b/FDTD/extensions/operator_ext_mur_abc.cpp
@@ -102,12 +102,12 @@ void Operator_Ext_Mur_ABC::SetDirection(int ny, bool top_ny)
 	}
 	else
 	{
-		m_LineNr = m_Op->GetNumberOfLines(m_ny)-1;
-		m_LineNr_Shift = m_Op->GetNumberOfLines(m_ny) - 2;
+		m_LineNr = m_Op->GetOriginalNumLines(m_ny)-1;
+		m_LineNr_Shift = m_Op->GetOriginalNumLines(m_ny) - 2;
 	}
 
-	m_numLines[0] = m_Op->GetNumberOfLines(m_nyP);
-	m_numLines[1] = m_Op->GetNumberOfLines(m_nyPP);
+	m_numLines[0] = m_Op->GetOriginalNumLines(m_nyP);
+	m_numLines[1] = m_Op->GetOriginalNumLines(m_nyPP);
 
 	m_Mur_Coeff_nyP = Create2DArray<FDTD_FLOAT>(m_numLines);
 	m_Mur_Coeff_nyPP = Create2DArray<FDTD_FLOAT>(m_numLines);