diff --git a/src/org/oscim/renderer/layer/ExtrusionLayer.java b/src/org/oscim/renderer/layer/ExtrusionLayer.java
index 7394c458..5f7f3b74 100644
--- a/src/org/oscim/renderer/layer/ExtrusionLayer.java
+++ b/src/org/oscim/renderer/layer/ExtrusionLayer.java
@@ -401,6 +401,10 @@ public class ExtrusionLayer extends Layer {
 	protected void clear() {
 		if (compiled) {
 			GLES20.glDeleteBuffers(2, mVboIds, 0);
+		} else {
+			VertexPool.release(mVertices);
+			for (VertexPoolItem i : mIndices)
+				VertexPool.release(i);
 		}
 	}
 
diff --git a/src/org/oscim/renderer/layer/Layers.java b/src/org/oscim/renderer/layer/Layers.java
index 8ee34daf..4fdd0c66 100644
--- a/src/org/oscim/renderer/layer/Layers.java
+++ b/src/org/oscim/renderer/layer/Layers.java
@@ -25,7 +25,6 @@ public class Layers {
 
 	// mixed Polygon and Line layers
 	public Layer layers;
-
 	public Layer textureLayers;
 	public Layer extrusionLayers;
 
@@ -87,72 +86,6 @@ public class Layers {
 		return ret;
 	}
 
-	//	public boolean uploadLayers(BufferObject vbo, boolean addFill, boolean limit) {
-	//
-	//		int newSize = getSize();
-	//		if (newSize == 0) {
-	//			// Log.d(TAG, "empty");
-	//			return true;
-	//		}
-	//
-	//		GLES20.glBindBuffer(GL_ARRAY_BUFFER, vbo.id);
-	//
-	//		// use multiple buffers to avoid overwriting buffer while current
-	//		// data is uploaded (or rather the blocking which is probably done to
-	//		// avoid overwriting)
-	//		int curBuffer = uploadCnt++ % rotateBuffers;
-	//
-	//		ShortBuffer sbuf = shortBuffer[curBuffer];
-	//
-	//		// add fill coordinates
-	//		if (addFill)
-	//			newSize += 8;
-	//
-	//		if (sbuf.capacity() < newSize) {
-	//			sbuf = ByteBuffer
-	//					.allocateDirect(newSize * SHORT_BYTES)
-	//					.order(ByteOrder.nativeOrder())
-	//					.asShortBuffer();
-	//
-	//			shortBuffer[curBuffer] = sbuf;
-	//		} else {
-	//			sbuf.clear();
-	//			// if (addFill)
-	//			// sbuf.position(8);
-	//		}
-	//
-	//		if (addFill)
-	//			sbuf.put(mFillCoords, 0, 8);
-	//
-	//		compile(sbuf, addFill);
-	//		
-	//		sbuf.flip();
-	//
-	//		if (newSize != sbuf.remaining()) {
-	//			Log.d(TAG, "wrong size: "
-	//					+ newSize + " "
-	//					+ sbuf.position() + " "
-	//					+ sbuf.limit() + " "
-	//					+ sbuf.remaining());
-	//			return false;
-	//		}
-	//		newSize *= SHORT_BYTES;
-	//
-	//		// reuse memory allocated for vbo when possible and allocated
-	//		// memory is less then four times the new data
-	//		if (vbo.size > newSize && vbo.size < newSize * 4
-	//				&& !limit) {
-	//			GLES20.glBufferSubData(GL_ARRAY_BUFFER, 0, newSize, sbuf);
-	//		} else {
-	//			//mBufferMemoryUsage += newSize - vbo.size;
-	//			vbo.size = newSize;
-	//			GLES20.glBufferData(GL_ARRAY_BUFFER, vbo.size, sbuf, GL_DYNAMIC_DRAW);
-	//			//mBufferMemoryUsage += vbo.size;
-	//		}
-	//
-	//		return true;
-	//	}
-
 	private static int LINE_VERTEX_SHORTS = 4;
 	private static int POLY_VERTEX_SHORTS = 2;
 	private static int TEXTURE_VERTEX_SHORTS = 6;
@@ -196,6 +129,7 @@ public class Layers {
 			tl.compile(sbuf);
 		}
 
+		// extrusion layers are compiled by extrusion overlay
 		//		for (Layer l = extrusionLayers; l != null; l = l.next) {
 		//			ExtrusionLayer tl = (ExtrusionLayer) l;
 		//			tl.compile(sbuf);
@@ -235,6 +169,7 @@ public class Layers {
 	}
 
 	static void addPoolItems(Layer l, ShortBuffer sbuf) {
+		// offset of layer data in vbo
 		l.offset = sbuf.position() * 2; // (* short-bytes)
 
 		for (VertexPoolItem it = l.pool; it != null; it = it.next) {
@@ -250,44 +185,28 @@ public class Layers {
 
 	// cleanup only when layers are not used by tile or overlay anymore!
 	public void clear() {
-		while (layers != null) {
-			Layer l = layers;
-			if (l.pool != null) {
-				VertexPool.release(l.pool);
-				l.pool = null;
-				l.curItem = null;
-			}
-			layers = layers.next;
-		}
 
-		Layer l = textureLayers;
+		// clear line and polygon layers directly
+		Layer l = layers;
 		while (l != null) {
-
-			l.clear();
-
 			if (l.pool != null) {
 				VertexPool.release(l.pool);
 				l.pool = null;
 				l.curItem = null;
 			}
-
 			l = l.next;
 		}
+
+		for (l = textureLayers; l != null; l = l.next) {
+			VertexPool.release(l.pool);
+			l.clear();
+		}
+
+		for (l = extrusionLayers; l != null; l = l.next) {
+			l.clear();
+		}
+		layers = null;
 		textureLayers = null;
-
-		l = extrusionLayers;
-		while (l != null) {
-
-			l.clear();
-
-			if (l.pool != null) {
-				VertexPool.release(l.pool);
-				l.pool = null;
-				l.curItem = null;
-			}
-
-			l = l.next;
-		}
 		extrusionLayers = null;
 	}
 }