diff --git a/LEGO1/lego/legoomni/src/common/mxtransitionmanager.cpp b/LEGO1/lego/legoomni/src/common/mxtransitionmanager.cpp
index 3e899233..c40787f8 100644
--- a/LEGO1/lego/legoomni/src/common/mxtransitionmanager.cpp
+++ b/LEGO1/lego/legoomni/src/common/mxtransitionmanager.cpp
@@ -388,12 +388,11 @@ void MxTransitionManager::WipeDownTransition()
 
 		// For each of the 240 animation ticks, blank out two scanlines
 		// starting at the top of the screen.
-		// (dwRGBBitCount / 8) will tell how many bytes are used per pixel.
 		MxU8* line = (MxU8*) ddsd.lpSurface + 2 * ddsd.lPitch * m_animationTimer;
-		memset(line, 0, 640 * ddsd.ddpfPixelFormat.dwRGBBitCount / 8);
+		memset(line, 0, ddsd.lPitch);
 
 		line += ddsd.lPitch;
-		memset(line, 0, 640 * ddsd.ddpfPixelFormat.dwRGBBitCount / 8);
+		memset(line, 0, ddsd.lPitch);
 
 		SetupCopyRect(&ddsd);
 		m_ddSurface->Unlock(ddsd.lpSurface);
@@ -427,9 +426,8 @@ void MxTransitionManager::WindowsTransition()
 		MxU8* line = (MxU8*) ddsd.lpSurface + m_animationTimer * ddsd.lPitch;
 
 		MxS32 bytesPerPixel = ddsd.ddpfPixelFormat.dwRGBBitCount / 8;
-		MxS32 bytesPerLine = bytesPerPixel * 640;
 
-		memset(line, 0, bytesPerLine);
+		memset(line, 0, ddsd.lPitch);
 
 		for (MxS32 i = m_animationTimer + 1; i < 480 - m_animationTimer; i++) {
 			line += ddsd.lPitch;
@@ -439,7 +437,7 @@ void MxTransitionManager::WindowsTransition()
 		}
 
 		line += ddsd.lPitch;
-		memset(line, 0, bytesPerLine);
+		memset(line, 0, ddsd.lPitch);
 
 		SetupCopyRect(&ddsd);
 		m_ddSurface->Unlock(ddsd.lpSurface);
diff --git a/LEGO1/lego/legoomni/src/video/legovideomanager.cpp b/LEGO1/lego/legoomni/src/video/legovideomanager.cpp
index 0ab5ba06..66a3b9b9 100644
--- a/LEGO1/lego/legoomni/src/video/legovideomanager.cpp
+++ b/LEGO1/lego/legoomni/src/video/legovideomanager.cpp
@@ -459,7 +459,7 @@ void LegoVideoManager::DrawFPS()
 			char* ptr = (char*) surfaceDesc.lpSurface;
 
 			for (i = 0; i < surfaceDesc.dwHeight; i++) {
-				memset(ptr, 0, surfaceDesc.dwWidth * surfaceDesc.ddpfPixelFormat.dwRGBBitCount / 8);
+				memset(ptr, 0, surfaceDesc.lPitch);
 				ptr += surfaceDesc.lPitch;
 			}
 
@@ -485,7 +485,7 @@ void LegoVideoManager::DrawFPS()
 				char* ptr = (char*) surfaceDesc.lpSurface;
 
 				for (i = 0; i < surfaceDesc.dwHeight; i++) {
-					memset(ptr, 0, surfaceDesc.dwWidth * surfaceDesc.ddpfPixelFormat.dwRGBBitCount / 8);
+					memset(ptr, 0, surfaceDesc.lPitch);
 					ptr += surfaceDesc.lPitch;
 				}
 
diff --git a/LEGO1/mxdirectx/mxdirect3d.cpp b/LEGO1/mxdirectx/mxdirect3d.cpp
index f9e0f74d..9ce37cf5 100644
--- a/LEGO1/mxdirectx/mxdirect3d.cpp
+++ b/LEGO1/mxdirectx/mxdirect3d.cpp
@@ -178,7 +178,7 @@ BOOL MxDirect3D::D3DSetMode()
 		unsigned char* surface = (unsigned char*) desc.lpSurface;
 
 		for (int i = 0; i < mode.height; i++) {
-			memset(surface, 0, mode.width * desc.ddpfPixelFormat.dwRGBBitCount / 8);
+			memset(surface, 0, desc.lPitch);
 			surface += desc.lPitch;
 		}
 
@@ -196,7 +196,7 @@ BOOL MxDirect3D::D3DSetMode()
 			unsigned char* surface = (unsigned char*) desc.lpSurface;
 
 			for (int i = 0; i < mode.height; i++) {
-				memset(surface, 0, mode.width * desc.ddpfPixelFormat.dwRGBBitCount / 8);
+				memset(surface, 0, desc.lPitch);
 				surface += desc.lPitch;
 			}
 
diff --git a/LEGO1/omni/src/video/mxdisplaysurface.cpp b/LEGO1/omni/src/video/mxdisplaysurface.cpp
index b5f7611a..850336e6 100644
--- a/LEGO1/omni/src/video/mxdisplaysurface.cpp
+++ b/LEGO1/omni/src/video/mxdisplaysurface.cpp
@@ -78,7 +78,7 @@ void MxDisplaySurface::ClearScreen()
 		MxS32 height = m_videoParam.GetRect().GetHeight();
 
 		while (height--) {
-			memset(surface, 0, m_videoParam.GetRect().GetWidth() * desc.ddpfPixelFormat.dwRGBBitCount / 8);
+			memset(surface, 0, desc.lPitch);
 			surface += desc.lPitch;
 		}
 
@@ -854,7 +854,7 @@ void MxDisplaySurface::Display(MxS32 p_left, MxS32 p_top, MxS32 p_left2, MxS32 p
 					MxS32 height = m_videoParam.GetRect().GetHeight();
 
 					for (MxU32 i = 0; i < ddsd.dwHeight; i++) {
-						memset(surface, 0, ddsd.dwWidth * ddsd.ddpfPixelFormat.dwRGBBitCount / 8);
+						memset(surface, 0, ddsd.lPitch);
 						surface += ddsd.lPitch;
 					}