diff --git a/vtm/src/org/oscim/layers/marker/ItemizedLayer.java b/vtm/src/org/oscim/layers/marker/ItemizedLayer.java
index 659f8229..154eef61 100644
--- a/vtm/src/org/oscim/layers/marker/ItemizedLayer.java
+++ b/vtm/src/org/oscim/layers/marker/ItemizedLayer.java
@@ -102,14 +102,7 @@ public abstract class ItemizedLayer<Item extends MarkerItem> extends MarkerLayer
 			int changedVisible = 0;
 			int numVisible = 0;
 
-			mMap.getViewport().getMapViewProjection(mBox);
-			for (int i = 0; i < 8; i += 2) {
-				float x = mBox[i];
-				float y = mBox[i + 1];
-				float len = (float) Math.sqrt(x * x + y * y);
-				mBox[i + 0] += x / len * mExtents;
-				mBox[i + 1] += y / len * mExtents;
-			}
+			mMap.getViewport().getMapExtents(mBox, mExtents);
 
 			long flip = (long) (Tile.SIZE * pos.scale) >> 1;
 
diff --git a/vtm/src/org/oscim/map/Viewport.java b/vtm/src/org/oscim/map/Viewport.java
index 01b22c91..5ae64d59 100644
--- a/vtm/src/org/oscim/map/Viewport.java
+++ b/vtm/src/org/oscim/map/Viewport.java
@@ -149,8 +149,9 @@ public class Viewport {
 	 * to screen corners by current view-projection-matrix.
 	 * 
 	 * @param box float[8] will be set.
+	 * @param add increase extents of box
 	 */
-	public synchronized void getMapViewProjection(float[] box) {
+	public synchronized void getMapExtents(float[] box, float add) {
 		float t = getDepth(1);
 		float t2 = getDepth(-1);
 
@@ -162,6 +163,17 @@ public class Viewport {
 		unproject(-1, 1, t2, box, 4);
 		// bottom-right
 		unproject(1, 1, t2, box, 6);
+
+		if (add == 0)
+			return;
+
+		for (int i = 0; i < 8; i += 2) {
+			float x = box[i];
+			float y = box[i + 1];
+			float len = (float) Math.sqrt(x * x + y * y);
+			box[i + 0] += x / len * add;
+			box[i + 1] += y / len * add;
+		}
 	}
 
 	/*
@@ -237,7 +249,7 @@ public class Viewport {
 	 */
 	public synchronized void getViewBox(Box box) {
 		float[] coords = mViewCoords;
-		getMapViewProjection(coords);
+		getMapExtents(coords, 0);
 
 		box.minX = coords[0];
 		box.maxX = coords[0];
diff --git a/vtm/src/org/oscim/renderer/MapRenderer.java b/vtm/src/org/oscim/renderer/MapRenderer.java
index a5c54836..ea4e8dd6 100644
--- a/vtm/src/org/oscim/renderer/MapRenderer.java
+++ b/vtm/src/org/oscim/renderer/MapRenderer.java
@@ -56,7 +56,7 @@ public class MapRenderer {
 		/** Do not modify! */
 		public final GLMatrix view = new GLMatrix();
 		/** Do not modify! */
-		public final float[] mapPlane = new float[8];
+		public final float[] plane = new float[8];
 
 		/** For temporary use, to setup MVP-Matrix */
 		public final GLMatrix mvp = new GLMatrix();
@@ -247,7 +247,7 @@ public class MapRenderer {
 			changed = viewport.getMapPosition(pos);
 
 			if (changed)
-				viewport.getMapViewProjection(mMatrices.mapPlane);
+				viewport.getMapExtents(mMatrices.plane, 0);
 
 			viewport.getMatrix(mMatrices.view, mMatrices.proj, mMatrices.viewproj);
 
diff --git a/vtm/src/org/oscim/tiling/TileManager.java b/vtm/src/org/oscim/tiling/TileManager.java
index 6b7fe28c..fe586d10 100644
--- a/vtm/src/org/oscim/tiling/TileManager.java
+++ b/vtm/src/org/oscim/tiling/TileManager.java
@@ -189,7 +189,7 @@ public class TileManager {
 		jobQueue.clear();
 
 		// load some tiles more than currently visible (* 0.75)
-		double scale = pos.scale * 0.9f;
+		//double scale = pos.scale * 0.9f;
 
 		int tileZoom = FastMath.clamp(pos.zoomLevel, mMinZoom, mMaxZoom);
 
@@ -205,12 +205,12 @@ public class TileManager {
 			tileZoom = match;
 		}
 
-		mViewport.getMapViewProjection(mMapPlane);
+		mViewport.getMapExtents(mMapPlane, Tile.SIZE / 2);
 
 		// scan visible tiles. callback function calls 'addTile'
 		// which updates mNewTiles
 		mNewTiles.cnt = 0;
-		mScanBox.scan(pos.x, pos.y, scale, tileZoom, mMapPlane);
+		mScanBox.scan(pos.x, pos.y, pos.scale, tileZoom, mMapPlane);
 
 		MapTile[] newTiles = mNewTiles.tiles;
 		int newCnt = mNewTiles.cnt;
diff --git a/vtm/src/org/oscim/tiling/TileRenderer.java b/vtm/src/org/oscim/tiling/TileRenderer.java
index 96ba5a59..4ae727da 100644
--- a/vtm/src/org/oscim/tiling/TileRenderer.java
+++ b/vtm/src/org/oscim/tiling/TileRenderer.java
@@ -124,7 +124,7 @@ public class TileRenderer extends LayerRenderer {
 		MapTile[] tiles = mDrawTiles.tiles;
 
 		if (tilesChanged || changed) {
-			updateTileVisibility(pos, m.mapPlane);
+			updateTileVisibility(pos, m.plane);
 		}
 
 		tileCnt += mNumTileHolder;